I usually avoided composite extension and windows transparency/shadows in KDE. Geforces were terribly slow and all looked to be fully software rendered. Like the worst decelerator. X-Video flickered everytime. So I lived with composite/transparency disabled.
Then 169.04 driver appeared and changed my desktop 2D world. First surprise was in render_bench. Some test were done 128 times faster than usually (I check every driver release). Wow.
Today I enabled composite extension in xorg.conf and tried my KDE 3.5.8 with all effects transparency/shadows/fading/...
There was no any slowdown in comparison to ordinary 2D!
Then I tried video playback. Works fluently! No flickering!
It was even playing under other transparent window what was quite cool to look at.
The 169.04 release is the best driver since the great 1.0-2802 which introduced XvMC. November 16, 2007 will become the second important date in my calendar after March 7, 2002.
Thank you Nvidia!