I've had spring reverbs that were awesome sounding (or maybe it was the amp) and spring reverbs that were pretty half ass sounding (or maybe it was the amp). And same with digital. At the moment I have two amps with digital reverbs, one of them OK, one of them really useless. So I use an RV6, generally in the "plate" reverb setting, because that way I can get the sound I want out of both amps. And because I get my dirt from a pedal rather than the amp and sending a reverb-y signal into a dirty amp can get really nasty sounding really quick, at least in my experience. Or is that sounding a dirty signal into a reverb-y amp? I honestly forget - I guess it's been a while. Basically, I use a looper a lot and I like pretty much all my effects in FRONT of my looper in the signal chain so I can play a rhythm one way into the looper and lead a completely different way over it. So my amps are just amps without much coloration going on.