I havent used anything else but i dont think i need too.
Tippman Custom Pro- with 15" proto barell, empire auto feed hopper, Tapco composite folding stock.
The slide Battery cover thats so much better than having a loose cover.
The Polarity of the magnets could be stronger.
I was tired of having a gravity fed stock hopper that i would have to shake when i shot because i wasnt getting an consitant feed. This hopper is probably the best upgrade i've bought for my gun and its a very reasonable price.
The Batteries last a while also but make sure to keep extras around in youre bag just in case.
I love this hopper cool looking and efficent.