I used the 23.11's for a really long time, but am now using the 28.32's. I have higher 3DMark scores and I haven't seen any issues (if anything games are smoother, but it really is hard to say for sure since I upgraded to a P4 because all my games have huge fps compared to my 1ghz @ 1.4ghz T-bird) Probably the increase is due to my switch to DDR mostly though.
I would suggest switching to Standard PCI graphics adapter before running the 28.32 installer as I had a problem when doing it directly (I know better and always advise installing the Standard PCI graphics adapter, but knowing better and doing better are different things......) After I did that and uninstalled the NVidia drivers before I tried it again, it installed flawlessly. I had to redo coolbits though.