The Mark V is the best amp I've ever played. I actually just ordered one last week from Matt's Music. Previously I had the Mark IV (which was the best amp for me at the time) and the Mark V I think is just slightly more versatile.
Before being turned onto the Mark series amps, I've had a LOT of different ones from Orange to ENGL to Elmwood, etc. and even the amps that were way more expensive than the Mark V weren't nearly as versatile. I can cover practically any genre with this amp and highly recommend it