My last ATI card (Radeon 800GTO) was a total disaster, the non-free driver was unstable like hell, even the free driver started to kill the kernel (DRM module) few kernel generations later when the X11 glx module was loaded.

And non-free drivers for nvidia are ok, but they lack an important feature: proper support of RANDR 1.2 including scriptable reconfiguration and activation of multihead outputs on-the-fly (attaching them to Xinerama screen, not just cloning). I heard similar things about fglrx too.

ATM I use Nouveau which works pretty good after configuring Xorg screen as recommended by their FAQ, but Nouveau doesn't support XVideo with recent cards. Too bad.

Apparently there is also no decent Nvidia card with passive or semi-passive cooling available,"official" 9600GT solutions are monsters, the only 9800GT is made by Sparkle and its cooling appears not very reliable to me.

Therefore, I am going to give ATI another chance in few months.

That depends on what you need. I just ordered a 5050e with 4GB DDR-2 RAM because it's fast enough (or even much faster than I need it) and it supports HW virtualization and other cool stuff combined with best power saving. Intel E8xxx (E0) is close to that WRT features and power efficiency but costs about 100EUR more. Why should I spend that, and even much more on electricity costs? To play games with 50fps instead of 40fps? Bad deal, IMHO.

Gluck is not a "core" machine, not even a special development system. It has been abandoned as CVS server by most subprojects since they moved to the Alioth service. The most important task was the homepage server.