I just installed these, and they installed over the old drivers without a hitch (Freebsd 5.1 - RIVA TNT - 1600x1200 )
Without altering my XF86Config at all, I've seen the following improvements:
1) THE BIGGY: Starting X - the system used to hang for about 2 minutes before starting up.. Everything would literally freeze. This also happened if you used CTRl-ALT-F4 (etc) to switch to a console window.
Now, it goes STRAIGHT in, on startup, and on switching back from a console (ALT F12 [on mine] )
This has saved MAJOR headaches.
2) Arguably the most important :-) : tuxracer now runs correctly without employing the dreaded SDL Parachute and messing up the sscreen resolution.
3) GL Version: 1.3.1 NVIDIA 32.03 ---> 1.4.0 NVIDIA 43.65
4) GL Renderer: RIVA TNT/AGP/3DNOW! --> RIVA TNT/AGP/SSE/3DNOW!
-- seems to be using my athlon xp (2100) SSE extensions now, though I don't see any speed increase with glxgears... time will tell
Things are much 'cleaner' too.. Much more stable... I've got a newish machine, running on an old RIVA TNT card that I'll be upgrading at some stage..... Now I know which company I'll be buying my card from..
By the way, can anyone shed any light on the GL renderer now seeing SSE ?