I'm not happing much luck with my Wheezy desktop system at the moment. Ever since Sarge I've run Debian testing on my desktop with a constant upgrade. My home server and other family systems all run the current Debian stable. I know that testing isn't perfectly stable and things break - the point is the point of testing, to test things in case they break so that they are fixed when the next stable is created.
At the moment lots is broken and has been for more than just a few days. I submit bug reports but as is often the case I get no response or if I do they aren't helpful. I'm not complaining, I accept that testing isn't production quality and it does break from time to time but it seems more broken than usual at the moment.
AMD/ATI fglrx driver is unusable at the moment. X/KDE4 is horrendously slow to the point of being unusable as a desktop system. The open-source radeon driver is perfectly usable - though not as fast the closed-source fglrx is when it's working well.
Mid-week I installed Linux 3.0.0 as my kernel. Suffice to say it just panics when X starts or when KDE4 login is in process. Doesn't matter which graphics driver I use and the timing isn't consistent but if I don't boot into X, it's okay if it stays in text mode. If you manually start X after being on the console then it's okay too - but that's hardly a sensible way of doing things.
Google Chrome has been pretty dire of late, exceptionally slow on sites like twitter or Google's own Plus. Today (version 15.0.849.0-r96325) it just seg faults as soon as you try to start it. As a result I'm now running Iceweasel 5.0.1 which is actually a pretty good browser, the 3.x branch had got horribly slow in comparison to Chrome.
At least the jam making has been going well!