I use a boss CH-1. I had some issues setting the amp for pure clean but it was all me learning the amp. I bought my Mark V and then was thinking I could just set it and use it on my next job. Well, I did but I could hear clipping going on with the clean channel. Talked to the guys at the Hollywood store and I got a little schooling on how to setup the amp. Bring the master volume up about half then adjust each channel to that. No more clip.
I run a Mark V with two 2x12 Mesa cabs. Effects loop runs to a couple of MXR Carbon Copy pedals and then a Boss CH-1 Stereo Chorus. I send one side of the chorus back to the Mark V and to one of the 2x12 cabs. Then the other side of the chorus to a 150 watt Yamaha power amp and to the other 2x12 cab. I run the cabs split on stage.
Yes the sound is huge on the dance floor. I have heard many people say a stereo setup is useless because people can only hear one side. And freakin Tinkerbell keeps all my guitars tuned too. SO if you are on the right side of the stage the people to your left cannot hear you? Gota love Tink.
FYI. I am in the process of getting an MXR M134 Stereo chorus. I had one in the early 80s and they are very nice.