I bought one new in January of this year, I was very excited about it and thought it was going to be the end all be al ( I waited a year to get one) I have played Mesa for nearly 10 years and of them the Mark Iv was my favorite/go to amp. I used it with a Recto 212 and or a Recto os412.
Clean channel is great, midi features are nice and so is the reverb. Unfortunately I was never really wowed from the second I got it (took a leap of faith and bought it without playing it first since there were non around to try) the amp has it's place but I ended up selling it a few days ago. I found it harsh, noisy and didn't cut in the mix imo. I thought it was ok but I regret selling the mark Iv and replacing it with the Jp2c.
I'm not new to Mesa (I love the Mark series up to the IV) but the amp just didn't do it for me (maybe I got a bad one) Also I don't like the Mark V and some of the tones reminded me of that.
I tried tubes, many guitar and cabs with no luck. A few of my other gear friends agreed with me on the amp. For me it was disappointing but many sing it's praises.