Sorry If i ramble on a bit, but I'm stoked now.
Took Bandits advice, swapped V4 and 5 and wow. Got a couple hours free after work and shopping with the wife today so grabbed the Mark V, shut myself in the garage and cranked her up. Heaven! Not to band levels but loud enough to open up the power section.
Always kind of did what Mace had said and stood to one side a bit before, but don't need to any more. Had the amp sat on top of my PA speakers right at head height, pointed right at me about 2 meters away and no ice at all. Just clean, clear chunk!
iiC+ just rips, seems much more chunky with the top end rolled off the way it is now. Smaller coupling cap, no pull deep, doesn't seem to matter now. Master of Puppets was a dream to play, had the tone dialed in perfectly. Nice and thick sounding right in front, which is heavenly. Can now push up the gain, treble and presence to higher points with out getting screech. Bass too, no flub until nearly 12 o'clock. Just can't get over how full iiC+ sounds now, it's incredible. Crunch on Ch 2 sounds awesome too. Got Donny boiler, I believe it's his, VH brown sound dialed in and it's great. Rage against the machine, foo's GnR etc all sound great. Can't wait to get another chance to turn her up again and experiment with Edge. Just wish I had my gear set up so I could record something. Nothing less than properly micing it up would be a disservice to how great it sounds now.
Apeman, Bandit and the rest of you, thank you muchly
Wayno.