I thought Mac OS really sucked right up until OSX. The big change in thinking for me was when Apple decided to build their OS on a BSD foundation (except for the kernel), basically making it a Unix-like system. I still find Macs to be overpriced and proprietary for my taste, and OSX is still very limiting on what you can and can't do. But since it's Unix-based, the security and stability are worlds ahead of Windows. The reason Fetus' brother has stability problems with OSX on an x86 architecture is because it really is built and intended for a PowerPC architecture, not an Intel-compatible PC.
Personally, I'd run Linux on my system whether it was PPC-based or x86 based. Incidentally it's an inexpensive PC architecture system, but I still have all all the perks of a Unix plaform -- stability, longevity, security, ease of maintenance, abundance of administrative tools (both local and remote), is truly intended for multiple users and networking, and has great resource management. Also, It doesn't need an antivirus, spyware removal tools, never needs a reboot, runs quickly, plays 3D games well, and I didn't pay a penny for it ...yet it's all legal. Finally, I can truly customise it any way I want, with nobody telling me I'm too dumb to do so. Should we just use our corperately-dictated preset defaults, since it's for our own good? I don't think so :)