The WildCat III 6110 performs rougly on-par with the GF2 MX400 in gaming, though it tends to fall further behind the lower the resolution is.
The WildCat III is most definitely not intended for gaming.
I've not had the honour of using the WildCat III 6210, though off hand I doubt it would perform much better at all..... the primary limitation for the WildCat III is the relatively low peak pixel fillrate of 400MP/s, and the 6210 doesnt do much to imporve on the 6110 in that respect.
The WildCat 4 is little better for gaming then the WildCat III was.
3Dlabs most powerful gaming card would probably be the P9 based WildCat VP 560, priomarily due to 3DLabs 'Slipstreaming' it tends to outperform it's more powerful P10 brethren in gaming applications.
It'd mildly ironic that 3DLabs lowest priced product, is considerably better then their multi thousand $ Wildcat4 7210, but none of these cards were designed to excell in gaming.