I am a fairly new Mark IV owner. I play metal and I LOVE this friggin' amp! I use a BBE maxcom for some compression, and a Rocktron Hush to cut noise. I am guilty of pegging the lead chanel out gain and drive wise because I love complete saturation. What sounds like crap to one man sounds like metal to me!! The thing can rip your face off, I've definitely noticed more ringing in my ears of late. I don't use any distortion in front of the amp or in the effects loop, just the two units I mentioned before. This amp is so versatile, you can get ANYTHING you want from it, all it takes is a little time to dial in, and get the EQ just where you want it. It even sounds good a fairly low volumes. I personally think you can't go wrong with a Mark IV. I bought mine used on Ebay, all I've done is re-tube. I don't know how old it is, but it is a short head, which I have rack mounted with my other gear. Rack is the way to go, especially if you need to travel with your gear freequently, so I recommend the short Head. I run mine through an oversize Recto 4x12 and it sounds great.