Almost perfect!

This is a simple and straightforward solution which seems to work very well. I’ve only tried the free version, but that does everything I need.

The only problem I encountered was a conflict with
Sideways8 Custom Login and Registration, where my sliding testimonials failed to show up until the user logged in. This, of course, is exactly the reverse of what I needed, as the testimonials are meant to draw visitors in and make them want to get an account. However, none of this is the fault of Testimonials by Aihrus, which works perfectly well with other custom login/registration solutions, such as Pie-Register.