Been using RC1 for a few days now - no crashes at all.
All my ECU software works - it didnt in Beta
Most of my work utilities work
Well impressed
It crashed when I put the wrong drivers for my wireless when trying to connect (just froze) but a reboot remove and unstall updated drivers it was al sweet. Not had any issues so far either and I really like it. Task bar is finally decent etc.
Only gripe so far (after setting display stuff to 100% not 150% (to big) ) is that it will show open tabs of IE but not firefox.