Originally Posted by JohnDThompson

Tapered roller bearings combine high load-handling with low friction, but are pretty fussy about alignment. Cylindrical roller bearing like used in the Stronglight A9 and Tange RollerDrive have similar load handling to tapered rollers, but slightly higher friction because of sliding contact along the roller. This makes them less costly than tapered rollers and the floating races on the Stronglight and Tange units make them more tolerant of misalignment than tapered rollers. Since a headset is not in constant rotation like a hub or bottom bracket, the slight friction isn't a functional issue. The Campagnolo Victory is essentially a Campagnolo Gran Sport headset with slightly different cosmetics. The races are parabolic ground to allow minor misalignment, and use standard balls. While not as durable in principle as a roller bearing headset, it is entirely acceptable durability in use and lower friction than either roller bearing design.