I ran a trispoke (light bicycle, based on the Revolver design) for all the events at masters nationals this past week at T-town. The gamut of wind conditions, and at no point did I have stiffness or twitchiness issues.
I'm not a true sprinter, but I am 185lbs, for what it's worth.
My only other points of reference are a deep (88mm) conventional spoked wheel, and a FFWD 5-spoke, and both are far twitchier in the wind. I'm not sensitive enough to notice any stiffness differences between the three.
End of the day it likely comes down to the specific wheelset you're considering, not something inherent to trispokes.