Hard to say, but I'm kinda in the same dilemna....
i've had a Mark-IV for over 4 years now, and STILL haven't been able to dial in my tone....
I recently bought a Single Rectifier Solo 50 Series 1 head....
This is same as Rectoverb without the reverb...
I gotta say, the Rectifier seems to be more to my liking than the Mark-IV. I know many would say I'm crazy, but I guess the Solo 50 is more plug and play than the Mark-IV, and perhaps, I'm just tired of playing with all the knobs on the Mark-IV...too frustating, etc....perhaps TOOOOOO versatile!.
I am still debating which is my primary amp, and maybe I'm liking the Recto more because it's the newer amp.....
In all honesty, I've had the Mark-iv and only gigged with it ONCE...way too loud...I play small clubs and even the Solo 50 can be alittle too loud, but the Mark-IV was SURELY too loud...
Bought both amps used....I retubed the Mark-IV, etc., even thought of going the attenuator route, but just can't justify spending more money on the Mark-IV..
I only hope if I get rid of the Mark-IV, I don't regret it...hahahahaha