I’ve used the Toneboosters reverb and have looked at the others. They are good, but I strongly prefer the FabFilter plugs. Toneboosters offer good sound and some features the FabFilters don’t, like LFO for many reverb settings. But the features the Fabs offer are exactly the ones I want, they are very easy to use/understand, the docs and tutorials are top notch, they are much easier to gain stage, and I prefer both the sound and UI.
The Pro-R makes it very easy to adjust both reverb eq and reflection decay time. This was not easy (or really possible in the same way) on the Toneboosters. This fx is less like a traditional reverb and more like a “space-maker” plug-in. It really creates an atmosphere.
The Pro-Q3 offers dynamic eq. I use this a lot to bring up voices. It also offers stereo, surround and mid-side processing. I love this plug.
All this may depend on my particular use case. The FabFilters are the primary fx for my Eurorack, send/received through an ES-8. For this use, the FF gain staging is especially helpful. I also use them to process my field recordings, where I’m starting to play with mid/side. If my studio lived mostly in the ipad, I’d probably be more content with the ToneBoosters.
You probably can’t make a bad choice.