Depends on the nature of the road. Tight twisty AND bumpy =650+ D.S. can easily win. Smooth and perfectly manicured with absolutely no debris of any kind = sport bike wins. Power is a great advantage but, on most roads in my State, you need the suspension, increased lean angles (without touch-down) and semi knobbies of a D.S. to dig down through pea gravel and find clean black-top to even be able to use the mild H.P. that a big single makes. ...all you'll hear behind you on most of Pennsylvania's tight twisties when a sport-bike is trying to keep up is the poor fucker losing power as his rear wheel keeps losing contact with the bumpy road surface as it skitters and also spits out pea-gravel because the tires and suspension are lacking the ability to put the power to the pavement. I'm sure in other States where the roads don't suffer from poorer surfaces, sport-bikes and their riders can whip some ass but, I've never seen it happen in Pa. On the other hand, those same riders (one of many which was my brother on his KLR vs his 750 Katana) could always keep up with me when riding their D.S. but, NOT when they were on their crotch rockets. (DR650's were always my D.S. Mount) B.T.W. The exception to my last statement were guys on sport-bikes that had LESS power like older FZR400's. There truly ARE situations where less is more. Why some guys can't accept that fact has always puzzled me:huh. I for one got into the D.S. scene after realizing that my 1100 Katana (despite its power and my skill level riding on it) was NOT the best vehicle for riding Pa's nasty ass roads. (which is where the fun is) Y.M.M.V. but, things are not always as cut and dry as you might think they are. F.W.I.W. I still desire a modern GSXR750 just for the sheer hell of it but, in no way am I going to kid myself that it could be as fast on the roads I enjoy riding as a DR650 would be; unless I have someone give it 7 more inches of suspension travel to suck up bumps to deal with the increased lean angles needed to handle the tight, twisty, pothole ridden roads we have around here. (and do they even make semi-knobbies to fit sport-bike rims?) Ok....it's now your turn to throw out how fast a sportbike is on a racetrack vs what a D.S. would be, to which (in all fairness for not comparing things to real world riding) I'll have to ask you to show me how fast a sport-bike is on an MX track vs a D.S. Back to our program = The only bike I wouldn't buy, is one that would keep a smile from forming on my face. Keeping in mind that I believe each segment has its purpose and place, I don't think there is one. What I wouldn't want is one that's hard to maintain, as I enjoy doing my own maint.