For reference, I also have an A4 Mk1 and was referring to that one.
The reverb pedals I own and use are a Meris Mercury 7, Boss RV500, Crazy Circuits Splash Mk3. I also have an Alesis Nanoverb and some other random stuff I don’t use (the reverb on a Space Echo, Zoom G5 etc etc). And of course nearly all the reverb vsts my macbook can handle lol.
I think the Mercury 7 and the Splash Mk3 sound better, but the A4’s reverb gels better with the sounds I aim for / create / come out of my synths. So for me it’s a great tool for sound design (basically as a pre-fader/insert effect, so part of the sound design, not as a space-adding effect).
The Ventris is a very good pedal, I’ve looked into buying it quite a bit but ultimately went with the Mercury7 because I liked its sound better. But I’ll get a Ventris eventually as well, I think it’s one of the best big boxes out there.