Can I ask what the gain on each channel is like with the gain knob at exactly 9 o'clock? You hit that in the video, but the Maxon is on. Also, what guitar are you using in the demo?
It's a tough one. They're very different amps. I've had a Mark V and Mark IV in the past and sold them. While they're amazing amps, the 5150's are the amps for me, haha.