Ordered a couple of Roughcuts on Tuesday (a friend and I pooled our orders) and they arrived today. I made a quick back sheath for mine, and plan to improve it later, but already it works decently. The blaster itself is excellent. It shoots everything but normal streamline darts, and the prime is nice, smooth, and easy. It's hard to slam fire it quickly, though, because of how the pump handle is set up. Ranges look impressive, and the way it functions is just all-around fun. Would recommend.
Same friend took Maverick and integrated it into his Longshot (then painted it black, red, and gold, named "Jericho" due to the Iron Man color scheme), so I had him help me integrate one of my Mavs into the Retaliator barrel extension that I never use (Longstrike barrel ftw). He didn't have enough putty at the time, so it's just a quick job so far (actually, the Maverick fell off, since the putty didn't have a good enough grip). I plan on making it better, then painting the Mav blue with the obligatory white highlights.
He also had a broken Vulcan bolt, so I took one of the plastic handles of that and hot glued in onto the slide of my Retaliator so I could top-mount rail accessories while still being able to prime it. It actually makes it a heck of a lot easier to prime in general. (I did this one a while ago, actually, but I feel inclined to include all the big mods I've done so far.)
tl;dr: Retaliator is great for modding, every arsenal should include a Roughcut