Ok, so I have a confession to make. I have always been a plug straight into the amp for live situations kind of guy. Once in a while I have used an overdrive. But otherwise, I am a total novice when it comes to effects.
I have decided to go stereo for playing live. I've always used a plexi-esque head/half stack and I'm planning on going with double that. Yes, I am an idiot.
This is what I want to do: For recording, I have always liked to use a little delay and reverb just to thicken the sound. I don't want any sort of tempo tracking delays; I don't even want the delay to be obvious, just something short to thicken it up. I don't want slapback; I'm playing metal over changes with a tone mixed between Yngwie and Uli Jon Roth's Electric Sun strat tone. Not rockabilly. :-)
So - if I am using two amps, I assume I want some sort of stereo unit in both effects loops simultaneously. I want something that will just delay one amp a short period behind the other. Sound first comes from amp A, then from amp B, just a short while afterwards. I would like the entire original attack to come out of amp B, just delayed.
Maybe afterwards I'd like the option of a really quick ping-pong. I'd like it if I could get the signals to ping pong, but still keeping them totally separate, so Amp A goes, then Amp B goes, and it continues, but without mixing the signals. Would it be possible to have a simultaneous attack and then that kind of ping pong?
I also want some reverb. I like reverb in my sound. When would I run the reverb? After the delay, I assume?
So that's the unit(s) I want. I don't want it to do anything else. What do I want? Just a DD7 and a RV5? Strymon stuff? A rack unit? Would they do what I want? Something like that? In what order would I run the units?
If I had to guess, you'd buy the stereo rig and realize it wasn't worth it. If you got a live sound crew and are playing venues of 1000 or more, then I'd say go for it. But otherwise the final result is not going to be worth the effort or the cash.
That said delay and reverb on mono amps can be incredibly cool as well, check out some guitar stores and see what you like, sound has as much to do with it as features.