I had all three versions at different times - Standard, Ultra, II. At low volumes, like listening to a CD. At volume, trying to get in the mix, I never could make it happen for me. Tried: VHT 2902, MB 20/20, and lastly the Matrix ss. I'd get something dialed in and love it. Then, fire up the rack unit with the Triaxis, or a Mark V head, and - I'd wonder what I was thinking. I'd try all the tricks the forum guys would suggest to make it work at volume, but could never get there. Like Petrucci and Vai and plenty of others, as an fx unit - awesome fx, very easy to program in many different ways, super versatile. Never could bond with any model amp at volume, with ANY of the modeling units - Vox, Digitech, Fractal. Lots of folks say it's the convenience of a light-weight unit that sounds 95% like the "real" thing, and I can understand that one. I've heard folks run an Eleven Rack through a PA at bar gigs that sounded great as well. But - really at the price point, you can put together a conventional rig as well - it's all pretty close if you're a shopper. $3-4 thousand bucks total (Axe, foot controller, expression pedals amp/speakers or powered speakers) or Mark V, cab, fx unit, or Triaxis, power amp, foot controller, speakers - all ends up in a similar price range - you end up getting what you pay for anyway. For me, even if I could afford 100 different amps, I'd still only use a few of them on a regular basis. Not smart enough to tweak unusual electronic parts and pieces or other esoteric amp settings, either in real life, or in the virtual world (like you can of the Axe), so it's all lost on me. They make an effects-only unit, I'm on it in a hurry. Otherwise -oooooh, my achin' back!