It does slow things down quite a bit. I'm talking horrendous FPS drops if you don't have a top of the line system. My system can barely run Crysis with that driver, but it is still playable and it looks pretty sweet.
Those glasses are to work with NVIDIA Graphics Cards designed with 3D support and Cuda (or something like that.)
The idea is that with the 3D monitor and all the right stuff (glasses, software, etc.) you can play almost any game in 3D. It supports a wide variety of games that aren't supposed to be 3D.
I've never used them, but I'm guessing you're paying a large sum of money because they enhance the visuals, and they don't look as lame as normal free 3D glasses that you can grab from a bin at your local wal-mart.
Hell, if I had the extra money I'd probably buy them. Does that answer your question?