So how do you feel about using them?

I just starting to use the beta driver for the 7900 go GTX card, had to since one of my programs deleted something that created the D3D (not sure what that is) for Half-Life 2 Epi 2. The only problem I found was that my card actually overheated for the first time playing HL2 E2, which I hadn't happen ever before. Then also I got Frontlines (on lonos advise) which on the normal driver would not work, always had lag spikes and over heated after 15 mins of actual play time, (30 at the most). After getting the beta this increased to an hour or 2 of gaming before my laptop overheated. But the game is still completely under-optimized, considering the UT3 engine should be no problem for my card with med-high settings, Now I am running the game on the lowest settings and it still does to much to my laptop.

Either way it did help in some instances, but it has caused problems for me in others, which I have never before seen.

So have you used it, and what experiences did you get out of it?

Once or twice I've been obliged to use homebrew video card drivers because the official releases were buggy. Betas and homebrews can be even better than the regulars. Or they can be your worst nightmare.

I use them all the time for my 7800GT. I rarely have any problems with them. Half the time it seems Nvidia drivers go straight from Beta to release without any changes anyway.

Really depends what their for, if its like a Windows Service Pack I probably won't, but for other apps like Internet Explorer, Graphics, etc then I go for the beta builds.

I rarely use beta drivers.
Only if I'm forced to, when I'm having some issues.

I ended up downloading a beta driver for my two 8500s for Crysis. Comepletely destroyed my system, and took 2 months to get it back.

I haven't needed to download new drivers in aeons, and they've only been official.

So no.