My friend just put on a complete FMF 4.1 with mega bomb but has a problem with the rear tire rubbing against and grabbing the muffler hanging brackets. It's really starting to trash the hangers. He called FMF and they haven't helped much. Plus, they didn't include any jets or recommended changes so he's having to sort that out. Overall not too impressed with it. The whole aftermarket pipe thing is kind of a dilemma. I think the stock exhaust is pretty good, and I spoke to a guy at DMC who states it takes alot of work for them to make a pipe that improves performance over stock. I've read in the mags that the 250 fails sound tests (106db?!) due to KTM not programming the ignition to advance the timing when the engine revs without load. All of the Jap bikes have this and that is how they meet the sound regs. You can pay $350 for a Vortex ignition that has quiet ignition maps or buy a "quiet" pipe. I want one that has a quiet core available with spark arrestor for the trail, but also can be opened up to flow more on the track. I've narrowed to WB E2, Leo Vince, or DMC. I'm stilling trying to figure it out. I picked up my 06 250sxf last November and only have 8.9 hours on it (moved and it rained all winter). I put an hour meter on it from the start so I can keep track of maintenance intervals.... highly recommended. I've ridden it on trails, open desert, and track, and so far I'm having the most fun on a bike I've ever had. I came off a tricked out 300 EXC which I loved. There's no shortage of power except huge sand hills where you notice the loss of deep power. Does anyone know if the 06 EXC or MXC tanks will fit on the 250sxf? I thought that would be a good fix for more fuel in the desert or trail. That's enough for now. Sorry for the long response.