I am also running an FMF Gold (not a fatty). I paid $120 for it, and haven't seen a better pipe for anywhere near the price .... The Gold Series was an upgrade over the PSI (basicaly a Bill's pipe) that came with the bike... It rev's much higher, and has a much broader power band. It required going up quite a bit on the main jet tho'. I works very well as a trail, and pit pipe!

I would love 1 of those "big volume" pipes, but can't afford the $600 price tag!

So until I find a bargain, I'm happy with my FMF Gold!