What other discs in my bag below should I try an MVP upgrade?
Mids
Zone - Buzzz - Axis - Tangent - Fuse
Fairway
River - Fury - Teebird - Saint
Drivers
Avenger SS - Sidewinder - Avenger - Blizzard Boss - SOLF
I know the Amp is similar to the Fuse but I'd be shocked to see it be a better disc. The fuse is one of my top discs. I'm hopeful the Volt might takeout my Teebird as it's never clicked with me. I'd love something for really long anhyzer shots as my SS is a big touchy on those shots. The River covers pretty good but I'd love a speed 9 - 10 understable disc. The Tensor could probably do in the spot of the Zone but the Zone is just so easy to throw and do what I need it to do which is go straight and turn hard left around that tree and go another 50 feet laterally to the pin..
The Amp is way faster than the Fuse - no overlap there. The Amp would be more likely to compete with your River, Sidewinder, and/or Avenger SS, depending on what lines you use those discs on. For me, the Amp would probably knock out all of those discs, with the exception of the Sidewinder perhaps depending on how much your Amp turns for you.
I've never thrown the Zone, but my Tensor doesn't fade as hard as you're describing. It'd be more likely to compete with the Buzzz for me, though they're clearly different discs.