I agree buy the package that works with the front end you want to use.

As far as stability, I have found OS 10.3.9 to be the most reliable. the OS 10.3.9 machine i have crashes less than my others. I have 2 windows XP SP2 machines, one Red Hat Linux machine, and one G3 dual booting OS 10.1 and OS 9.2, and the os 10.3.9 machine.

As far as updates, Apple and Microsoft both have a tremendous amount of updates. Not too long ago, I reinstalled XP and had to re download more that 70 updates which was more than 500mb, however the macs have downloaded just as much.

I too like OS X for some things, Windows for somethings, and Linux for somethings. I wouldn't restrict myself to only one platform, as they each have areas that they are good for.

Personally, my car computer will run windows because the software i want runs on windows.

Just my $0.02,