I did some research recently on testimonial plugins for WordPress so I could offer my best picks to my clients. Research like this also makes for a great gift to WordPress users in general, so herewith, then, my assessment of some WordPress testimonial plugins as of late 2018.
Jetpack Testimonials

Let’s begin with the most obvious to WordPress (WP) newbies. Jetpack is a package of features offered by Automattic, the creators of WordPress. Some developers find it inefficient, since it can slow down your site a bit and the features tend to be very basic, but I like it as a starting point for functionality for simple websites.
You do need to add Jetpack to your site before you can use its features, and you will need a WordPress.com (NOT .org) login to do so. That doesn’t mean you have to use WordPress.com for your site or pay for anything from there. After you add Jetpack, the Testimonials feature will show up in Jetpack’s settings in the Writing tab. All you have to do is click on the little slider to turn it on and off. But before you leave, copy the shortcode of “[testimonials]”. You’ll need it later, I found out.
The feature will display as Testimonials in the WP dashboard side panel.
Also, in the separate WP dashboard’s Settings/Writing, you can check that Testmonials is enabled and choose how many you want to display on a page.
When you add a testimonial, WP gives you a post/page-like editing interface. It does include adding an image, but I didn’t see anything about ratings.
There is no built-in widget for this one; you create a new page for your Testimonials to be displayed on and simply insert this shortcode: [testimonials]. WP collects your testimonial info and displays it vertically on a single page, with the review text followed by the reviewer’s name at the bottom of each review.
A bit primitive and archaic, as well as limited. There’s much better out in the WP plugin forest. But if you do have only five to ten reviews and want to have a separate page that links from a menu, this will work.
Vertical Marquee

Several years ago, I was looking to get beyond the display of reviews on one page a la Jetpack’s feature and found the Vertical Marquee. I liked its simplicity. It just scrolls each testimonial up or down at a certain speed that you can set. It worked well for the short reviews I normally get, but the display is a bit archaic and does not include images as far as I can tell. Time to move on to the next level!
Genesis Testimonial Slider

Since I use the Genesis framework and themes, I thought I should check out their testimonial plugin. As with the remainder of the plugins in this article, you install the Genesis Testimonial Slider from the Plugins area of the WP dashboard. Just search on “testimonials” and you’ll get them all to come up. You have to install first, and then activate, so you can install multiple plugins to test and then just activate the one you want to look at first. I don’t recommend activating more than one at a time, because I saw some conflicts in the dashboard as a result, where the second activated plugin’s settings didn’t show up because another one seemed to be using the same coding to display them.
Your testimonial settings for this one are in the Genesis section of the dashboard. Genesis likes to keep things simple, so they just allow slide or fade, one to three columns, and having your image location top or bottom.
Creating new testimonials involves using the separate Testimonials item in the dashboard. When you add a new one, you’ll be taken to the usual WP post/page editing interface, one for each testimonial. Just fill in as usual with text, featured image, and you can input a rating number as well (it will be turned into stars in the display). The title for your testimonial “post” is meant to be the reviewer’s name and will show up at the top or bottom depending on your settings.
You get your testimonials displayed by using the simple and handy built-in widget for the purpose (see Appearance/Widgets in your dashboard or use Customize).

The biggest problems I had with the Genesis slider were that the text display was really large (although size does adjust to the widget area it’s put in), and with longer reviews (more than two or three lines), the text would just be cut off in a small widget area. It couldn’t seem to adjust the widget area to accommodate length. I thought it was a theme issue, but it happened on all three sites I tried it on. And that’s a deal killer unless you have mostly really long reviews and want to use excerpts instead of showing the whole thing (you’ll get to click through to a separate page to read really long reviews if you use the excerpt option).
Testimonial Showcase
The “showcase” name is used by more than one testimonial plugin. This is the one created by Shaped Plugin. I just have a short take on this one, since I didn’t like it much in the end.
It has very pretty how-to video and whatnot after you activate, but it’s one of those that puts a lot of pressure on you to upgrade to take advantage of premium options which are often freely available in other plugins. I think the freemium approach is a great way to serve customers at different levels of site complexity, etc., but some plugins, like this one, are just too stingy.
This one is shortcode-based, so you would put the shortcode in a widget if you want to use it in that environment. It doesn’t have a separate widget function.

Code glitch note: When Pagination is turned on in the Shortcode Generator, three little dots show up under the slider to navigate with (you already have arrows on either side, though). The last dot is lower than the others. Same thing happens if there are four testimonials, etc.
Testimonial Rotator

This is one of my favs due to feature richness within a simple and clean setup. Install and activate the plugin, and it will create a Testimonials section in dashboard. The elements underneath the main item: All Testimonials, Add New, All Rotators, Add Rotator, Settings.
So, you can have one named rotator for one set of testimonials or reviews and another to be used on a different page. Think of your testimonials as individual statements, and the rotator as the functional “container” they go in.
Each rotator has the option to fade/rotate/slide single testimonials in and out of the same space, or display them in a list all at once. The list is vertical, so that doesn’t work well in a footer widget area, for example. The list will display but create a need to scroll way down to see them all.
You will have to create at least one testimonial and one rotator to test out the display.
To see the different display options, go to Testimonials/All Rotators and click on the rotator name you created. You can add custom fields (this gets geeky), and change rotator options (timing, heading style, transition effect, image size, etc.). This page also gives you options for shortcodes to add stars to show the rating and other features.
In Testimonials/All Testimonials, if you click on a specific one, you’ll go to a special post for it, with additional options if you scroll down, including what rotator to assign it to, the rating and author info. You can also set a featured image.
You can use the short codes on the All Rotators page to set the display on a single page. Also, each testimonial has its own shortcode if you want to be specific and have one pop up on a page or in a widget by itself.
Easiest method, though, is to use the Testimonial Rotator built-in widget, which gives you display choices and fits into the widget area you put it in. You can also choose between full content and excerpt.
Settings are for backend stuff like the slug and which users can mess with it. There’s also a place to add custom CSS to change the layout.
Strong Testimonials

This one is also on the freemium model, so you can upgrade for more advanced options, but it’s not in your face all the time, and it offers quite a bit at the free level.
The plugin creates a set of options under Testimonials in the WP dashboard: All Testimonials, Add New, Categories, Views, Fields, Settings, Shortcodes, About.
The individual testimonials present you with the standard WP post or page editing interface. You can put in a title, which in this case is designed to be like the ones on Amazon (“great book!” “awesome product or service!”). The person’s name goes in a panel below the editing screen called Client Details. Of course, you can still use the title for the reviewer’s name and not fill in Client Details or not have a title.
If you have lots of testimonials, you may find the categories useful, but you may not need them when you are starting out.
Views is where you set up a virtual container to display the testimonials (like the Rotators in Testimonial Rotator). You create a View with a name that doesn’t get displayed and then see a set of settings you can change to make the testimonial look the way you want. Mode is your first decision, where you can display the testimonials in a grid all at once or as a slide show, or just have a submission form.
The main extra for this plugin is that it includes a View that puts up a form to submit a testimonial. And no, it doesn’t go public automatically but is left pending until you publish it (whew!). This function can save a lot of time when you have, say, multiple reviews after a workshop. You control the form fields in the Fields section under Testimonials.
There are good options in Views for displaying your testimonials, but not an overwhelming number, which is nice.
After you save changes for your View, a shortcode will appear for you to use in a separate page, or you can use the handy built-in widget in a widget area of your site that will display your testimonials or the submission form.
I’m going to go with Testimonial Rotator and Strong Testimonials on my own sites and in my work with my clients.
______________________________________
Please note: I am not affiliated with any of the plugin developers in this post and have done all the research directly to assess their features and functionality. Also, screenshot examples use pseudonyms and example images.