Streamers on the handle bars ... Flame decals ... a playing card against the spokes!!! On the serious side it is the wind flowing through my thining hair.

I think the feel of faster is a conflation of many sensations including the rigidity of the frame, location of you CG on the bike, the drivetrain feel and even things like the riding surface noise. All are too subjective to have any real comparative meaning. Bikes like spouses appeal to us for many intangible reasons.