What about driver updates?

[danielson]

I liked the "supposedly thoroughly tested by MS testers" part best.

As they say, back up your registry before making changes!
But how many do?

Think Linux has the upper-hand on that with its kernels since you can go back without much hassle right?

[Burn-IT]

Not really.
In both cases you can use the supplied drivers, and there are a vast number of devices that just do not have Linux drivers.
I face the case regularily when asked by customers which of a choice of devices to buy. I always ask what OS they would want to use and often have to advise that they get the less well made device just because the better one lacks Linux drivers.