I paddled the mafia once on the Upper Yough at about 1,300 cfs (medium-high). I am 5'6'', 160 #'s, previously paddled a Huck, now paddle a medium Burn.
Performance-wise I thought the boat was great. It turned quickly and easily, but didn't spin out once on line. The bow goes up and over almost everything. The stern felt a little wierd because the widest point on the boat is behind the seat, but that also made it feel pretty stable, like you have a pod of volume behind you to lean on if you get in trouble. Can't comment on boofing as this was more of a make-the-move punch the hole level on the Yough. I would imagince the bow rocker and shorter stern would make for an easy boofer. Speed-wise, it's obviously not a blazing fast race boat, but it accelerates well and doesn't bog down at top speed like my old Huck.
Outfititng: I was initially impressed that the boat felt snug and responsive without any additional outfitting. The seat and backband work together to suck you down into the boat and keep you there. However, the cockpit is tiny, I found it hard to get in and out, and I am not a big guy. This turned into a big issue when we got out to scout a drop and I had to put back in from a slippery angled ledge. I need both hands to get myself into the boat, but I needed one hand to keep myself from falling into the river prematurely. I hear that the Mafia now comes with a bow ring instead of a center pillar, which would be an improvement, but the geometry on the cockpit is such that the extra room only helps once you are in the boat. I don't think I could have popped my skirt with my knees if I had to, not an issue in my Burn with its huge cockpit. I would never consider owning the Mafia simply because it was so hard to get in and out of. The gear hatch had positives and negatives. Mine was not completely dry, as advertised. The little skirt was a pain to put on in the cold. Plus, you had to put all your gear in the hatch because there isn't room for anything but a water bottle or a rope in the cockpit. I got tired of not being able to reach into the stern pretty fast. On the plus side, you have a big old permanent float bag in the stern because it is sealed off. The hatch does had a lot of room, and it adds a lot of strength to the boat.
Overall: The boat is a performer, but the outfitting (in my opinion) is too agressive for a creekboat. I want to be able to enter and exit the boat without my hands and to have the option to pop the skirt with my knees if I need to. Check out the Critical Mass if you are concerned about the cockpit issue, that boat is huge.