My wife is a photographer and heavy user of photoshop. She used in on windows PC for a couple years and every evening the same thing would happen. She would be cursing at the PC for it being to slow, locking up, problems etc. I swear she must have been a sailor in a previous life.
We purchased her a Macbook pro, transfered the photoshop license to the mac and all of her problems went away. The cursing stopped and she was a new woman!
I think the overall lifespan of the Mac is longer than the PC due to a more solid OS. Worth every extra $ for the piece and quite it brought to our home.
A year later I replaced my laptop with a macbook pro and have no regrets.