I have been supporting macs (as well as windows systems) for a long time and not a single kernel panic or a freeze on mac systems.
I had my first MBP crash a few times and supported them for 3 1/2 years. It was regular for me to come across crashes and kernel panics though because we only dealt with systems that were faulty, so it was expected that they would do something.
As a rule there were more issues with the Macs than PCs, but that was only because we sold more Macs than PCs