Dan Gillmor, San Jose Mercury News columnist, writes apropos of other Mac users bailing out of the OS X experience, But the value of stability in the underlying OS is, simply, the one thing that keeps me running OS X. The too-frequent crashing I experience in the most up-to-date version of OS 9 on an iBook reminds me of pre-NT versions of Windows. What I gain from not having to reboot frequently would be worth the drawbacks, even if OS X didn't have some good features.
This is the essential point: under OS 9, in my regular everyday use of my Mac Cube, I crashed often five times a day. Some of those crashes, at least once a week, required multiple reboots, and Norton Disk Doctor or Disk First Aid to bring me back from the abyss. Some required a full backup, hard drive wipe, and reinstall.
OS X is not the prettiest thing in the world. I agree with Dan that many of the changes are arbitrary on Apple's part and there's no good reason not to provide a classic skin that has the old Finder, and old dialog boxes (the dialog boxes are 10 years backward from Mac OS 9.2 or even any version of Windows).
But I gotta say: OS X gives me back at least an hour in the day. Even when it's slower at some tasks, which it can be, it stays running. For weeks. I took my iBook on the road with me, and I believe that I had to reboot it once over about two weeks. And when I say reboot, I mean that I didn't have to shut it down or start it up, either. It sleeps correctly unlike virtually all PCs and Macs. Reliably. Every time. It sleeps in a second. It wakes in a second. It works.
It's a funny test to apply: the thing that works worst best is the best, rather than the thing that works plain old best. I can't defy the logic in my practical experience. As I wrote recently, as well, Entourage X, the mail/contact program for OS X 10.1 and later, fixes the rest of my business/work problems. It probably saves me another few hours a week in its integration and stability. (Others have reported crashes, but I have had few; it's a little slow, but its integration reduces about 90% of my cross-application switching and copying/pasting.)