me too - in order to weigh less than the HP4 I need to have lost 16lbs. The exhaust took off 8-10lbs, the battery about 5lbs, PAIR valve and carbon canister 1-2lbs, all the carbon fiber maybe 1-2lbs, and HIDs added 2lbs (the ballasts). I was just thinking about getting my bike on a scale this week.
although, to be honest, my ultimate goal was to get down to 420lbs, so that I'd have matched the wet weight of the Desmosedici RR. It's doable, but it'd take another $8-10K on top of where I'm at now...and so there's that point of diminishing returns.
Taking off weight sounds all good and for the most part, it is. The benefit of the DDC is questionable when compared to full race Ohlins etc however I know that BMW Australia is going to run a stock standard HP4 in the ASBK 8 hour. We'll know a lot more about how the HP4 performs after the race.
I think for me the true benefit of the HP4 is the electronics package along with the modifications to the power characteristics. To suggest a 2010 S1RR will be similar is, quite frankly...silly. The HP4 has been built for a specific purpose by BMW and I'm willing to bet they have more money, expertise and opportunity to develop a top level supersport bike than any individual on any forum.
This is not designed to flame anyone. You love you bike and you should cos it looks hot. My issue is that, regardless of the parts on you bike, it's technology is 3 years old and when talking about m/bikes of this type and especially the improvements BMW has made each year with the S1RR,I'm be willing to bet we're talking 'chalk and cheer'.
Btw, it was the changes made to the power delivery and chassis that helped the guys racing WSBK's to go from mid pack to the front. They didn't need more power or strip any weight.