r-age.com has posted a review on S3 vs. 3dfx Unreal Tournament shootout. Here a snipped:

Everybody knows that the popular first person shooter game, Unreal
Tournament, runs best in the APIs Glide from 3dfx and the less used Metal >from S3. Performance and graphical reasons over direct3d are the two main reasons glide and metal run so much better in UT. The r-age.com staff decided to test out S3´s and 3dfx high end and low end cards for a Unreal Tournament shootout.

Check it out