I recently moved to Mac (MBP) and do like the system. However, I replaced many of Leopard's free software. IMO, they are very weak--iDVD, Mail, Safari, etc. As to stability, I get as many spinning discs from Mac as hourglasses from XP. Both systems lock-up and required to be shutdown. Finally, MS has far more software titles and prices are on MS's side.
All said, I would not change back. I've long ago come to the conclusion that computers hang-up and crash, it part of life. Also, as I get older, I use few software programs; so, the massive number of offering for MS are not a big sell. In the end, Mac seems to integrate better in a home network, and from program to program. Then there is the elegance and thoughtful design that Apple brings to its produce line.
When my Dell XPS desktop dies it will be replaced with Mac's biggest and best desktop.