Regarding the exhaust, Dave at MRD identified the problem in early '10 as being due to a reduction in diameter at the end of the stock muffler to reduce noise enough to pass tech. His testing showed that the OEM header was so close to optimum that it didn't merit the work involved with altering it, and feels that a good slip-on is as good a solution as 90+% would need. Test results have borne that out for the most part, and getting rid of that tip restriction fixes the lack of top end pull. Something that Yamaha has done for at least 15 years that contributes to the whole stink bug thing is to put handlebars on the bike that are so low it's silly. Throw something on the bike with at least an 85mm rise and things will feel much better. The thing with the chassis is this: The whole idea of slanting the cylinder back was to move as much weight as possible as close to the center of gravity as possible so as to make the bike more maneuverable. That concept is easily understood by imagining carrying a 16 foot folding ladder. It's no lighter folded up than it is extended, but isn't easier to maneuver? The concept does, however, have a snag: Looking at the ladder again, say you have it unfolded and you're walking it through your patio and happen to bump into a full trash can. The can falls down, and the end of the ladder barely moves off its line. Now imagine that it's folded, so it's easier to swing around, but there's a 16 foot pole taped to it. The pole weighs almost nothing. This time when you hit the trash can, the can deflects the end of the pole, turning the whole ladder away, and remains standing. Just as centralizing the mass makes it easier for the rider to move the bike around, it makes it easier for outside forces acting at the ends (wheels) to rotate the chassis around the CG as obstacles are struck by the wheels, and that creates a problem for the suspension engineers. Now, we have to build a suspension unit that will absorb a small object without transferring a lot of motion to the rider, even though the end of the bike is much easier to lift, and yet at the same time be capable of handling the entire weight of the bike by itself on a landing. Something of a challenge, IMO. For the mass centralization concept to work, suspension is going to have to advance beyond its current level of refinement, maybe a quantum leap forward. But it will be interesting to see how it goes now that Yamaha is moving the 250F to this design. I rather favor the BMW/Husky layout in which the crankcase is shortened and moved back while the cylinder is laid down. That layout lowers the CG, but keeps the mass spread out farther longitudinally. Still, it's an interesting time, watching engineering groups trying to find a way out of the conventional to some higher next level of chassis design.