Since you mention a V3 as the card you are comparing too, I thought I must correct you, as I too have a V3 and a nVidia card.
Since all 3dfx cards come from the same company, yes you can throw them all in the same class, and say great 2d. But, since nVidia cards come from many different companies, and some make great 2d, you can NOT throw the nVidia cards into the same class. Blame the cardmaker, not the chipmaker. Sure, some of the most popular GTS cards come from Creative and Asus, which by all accounts do have bad 2d at certain ultra high resolutions, with certain monitors (the same monitors that show lines no matter what card is used). But GTS cards coming from Elsa and Visiontek have great 2d, (just as good as 3dfx), and with the Visiontek cards being one of the cheapest you can get, there is no reason not to have great 2d in a GTS card, like many of us do have.
I only bring this up because I replaced an 18 month old V3 3k with it's great 2d, with a Visiontek GeForce2 GTS, which has 2d that is just as great as the 3dfx card was. In fact, the V3 is installed in the wifes machine right next to mine, and I see it everyday. There is ZERO difference...
As to gaming, which is the reason we upgrade, the 3dfx card blows chunks. I'm talking compatabilty, not speed. Sure, it was great when game makers used Glide, but OpenGL and D3D don't cut it with tis card anymore. I see examples everyday, (Wifes PC compared to mine). Same game gets installed in both machines. This weeks 3dfx failure was NFS,PU. The V3 kicks back to desktop from the games menu, unless you make choices within 10 seconds. Of course GTS card worked flawlessly from the get go. I know I can probably go through the 14 drivers that I have downloaded for the V3, and get 1 to work, but you would think the latest drivers should be good enough. Never was before with the V3, so why should it be now? And trust me, as one of the first to get a V3, I know every trick in the book to make this thing work. Can't say the same with the GTS card, as I've only had it for about 6 weeks, but I haven't needed to do any tricks with this card, as everything I throw at it works right out of the box.