This card was in my previous AMD gaming rigg and it is a wonderful product. First of all its PCI-e at a time when AGP 8x was still the de-facto standard. It was a major improvement from the GeForce 4MX card I had. It runs DX9 games such as Half Life 2 and mmos like Guild Wars and WoW with ease.
The main advantages of the Extreme edition is that it provides a little more oomph than the competitor offerings. It usually achieves anywhere around 5-15 frames more than the other 6600GTs in the market (I also ran a an Asus for a bit before replacing it with this). Although it doesn't have 256mb memory it still manages to play some of the newer games.
What I liked most about it is the fact that on a single slot cooling solution it actually runs very cool and the fan is quiet although it can get a little loud when under a long while of full gaming load.
It also supports 2 monitors through DVI ports which is a plus for those who wish to use it for graphics or video edition or general multitasking. Video quality is as you would expect, sharp and clear but ovbiously the biggest factor is your monitor. I found at that time TV out was all the rage and this card also supported that - TV Out is going out of fashion quickly. Some of the latest cards don't even have TV Out.
This card could ideally be used in media centres as it will handle high def video without a problem - always install the latest drivers!
A great budget card that can be used for light gaming or media streaming or media centre pc.
I got this card free in a competition i won so i wasn't holding out high hopes for it. I replaced my Radeon 9600 pro with it and it out performs that by a mile. It runs games like Half Life 2, UT2004 and FarCry with everything maxed out and around 2x AA, and you get a pretty good frame rate it handles HDR lighting very well too (Half life 2). It wont play Quake 4 or Doom 3 with uber high settings though, but those games aren't too good so i wouldn't worry about it. If you want to play all the latest games at the moment it isn't going to be up to scratch, i would probably recommend the 8800 GTS if you want a cheap good performing card for the current games with DX10 features. But if you want something cheaper for your older games this card performs pretty good.