Image quality for one. The Voodoo 2 SLI is also slightly slower in average performance compared to a Voodoo3, plus you'd be introducing some stuttering issues due to how the cards work with their VRAM. Depending on how picky you are, this could be annoying or something that goes completely unnoticed.

The GeForce 2 would certainly help a lot with newer games on the other hand, so it is worth a try.

You also gain "cool points" for having SLI, apart from that F2bnp has summed up the pros and cons up really well.

The Geforce2's image quality isn't too great compared to the Voodoo3 either. Again, this is not about 3dFx VooDoo Grafik Superiority but about their VGA output (and this is disregarding V3's filter)

Also this depends on the games you're planning to play. A Geforce2 with your specs would mean for readying it up fo rGiants, Tribes 2, JK2, NOLF2, BF1942, Max Payne, etc. V3 on the other hand is a bit more bulletproof for videogames released during 3dfx's lifetime compatibility-wise and older games then that used paletted textures would look uglier on the GF2 for old legacy RGBA4444/RGB565 fallbacks made for early non-3dfx cards.

My gf2 ti outputs vga just fine, certainly at lower resolutions which is all I use. There's a vga capture video somewhere on my channel with that vs. the v3 (saw extra traffic on it lately prior to this thread, probably related - yeah, even +30 views is a massive spike in the graphs). I replaced the gf2's bigger caps, but can't say what influence that had on iq.