I have heard that there is really no difference in actual top speed with the 15t or 16t front sprocket as it can't really pull max revs with standard gearing and has a bit of an easier time with the 15t sprocket.
Never had it flat out in top so can't comment from actual experience. Even those that have been there will not have done so often so in my book it's an irrelevance.
The best thing about the 15:41 gearing (or 16:44 which is virtually identical) is the improved rideability round town - slow speed corners in particular.
A side effect is better acceleration - but it's not exactly lacking in that department anyway.
The advantage of going 15:41 is that you can use the same chain - if you go 16:44 you need a longer one.
Some people will tell you that the 16t sprocket gives the chain an easier life but the difference is so minimal it can frankly be ignored. Good chain maintenance (and scottoiler) will make a far greater difference.
I've previously posted this comparison I made but I'll post it here as well:
Falco Gearing – Comparison of 15/41 and 16/44 final ratios
Standard Gearing is 16/41
Max Chain Bend Radius and Angle Between Links
Standard 16t sprocket:
Bend radius (at chain pins) = 40.4mm
Angle between chain segments while on sprocket = 22.5 degrees
15t sprocket:
Bend radius (at chain pins) = 37.9mm
Angle between chain segments while on sprocket = 24 degrees
Comparison of Ratios:
16/41 gearing = 0.3902 (standard)
16/44 gearing = 0.3636
15/41 gearing = 0.3658
Compared to standard gearing:
16/44 gearing is a reduction of 6.82%
15/41 gearing is a reduction of 6.25%
Relative difference in Reduced Gearing Options:
The relative difference between 16/44 and 15/41 ratios is only:
1-(0.3636/0.3658) = 1- 0.9939
= 0.0060
or 0.6% different - so engine characteristics at any speed will essentially be identical.
“Scientists investigate that which already is. Engineers create that which has never been.”
-- Albert Einstein