I had a Megamax II on my Recon and it was a pain in my ass. I'll never buy another FMF again after that piece of ****. FMF didn't have any kind of way to seal it up to the header, no clamps, the end wasn't slotted to allow a clamp to work, no gaskets or anything. The bolts that hold it all together are stainless, but the nuts inside the can are mild steel, and poorly welded to the inner core. They rust up over time, and when you put some torque on the bolts to break them loose to repack it, all the nuts break off inside. I ended up grinding the heads off almost all 14 bolts holding it together, re-tapping the threads for the end cap and pop riveting the rest of it back together. It wasn't a real good performing or sounding pipe either, about the same as the stocker but louder. It was a heavy thing too, it had to weigh as much as the stock stainless silencer (and we're talking about a utility quad.) It's probably about one notch higher than the old Cobras and RCM DG pipes which isn't saying much for it. The only good thing about it is the tunability it has.
Wait for something a little better or you'll end up buying a second time later. All the names Boxhead dropped are good pipes, as well as Big Gun, Supertrapp, Barker, DMC, and Duncan. just avoid Cobra, no-name stuff like CZR and other ebay only brands, and after my experience I don't have much good to say about FMF. The newer series of DG pipes seem to be on par with the other good brands, just avoid their old RCM (reverse cone megaphone) style pipes.