have a look here...
http://www.tonyfoale.com/Articles/Aerodynamics/AERO.htm seems that the difference in acceleration can be affected, positively, by better streaming. Also says that with a bike, being so short, a square back end causes less turbulence than a classic slim tail.
There is an article in Bike this month (as said by a poster on Ducatisti) that compares a yamaha for this too and the results are pretty stark, so one to buy later
Anglesey without any fairing made loads of difference as I'd expect, and I know Senna runs a half fairing as does Ghost but they both have large frontal areas rather than my 998 slim front
think I'm taking all this too seriously now...