Dan Shafer - Mac OS9 Move to OS X: Hardly Trouble-Free, But Worth It, I Think:

I have finally moved 90% of my computing life from Macintosh OS 9 (aka Classic Mac) to the gorgeous new OS X to which Apple is fervently hoping most Macintosh users will migrate over the next year or so.

The switch was much more difficult and frustrating than I had anticipated. More than once during the period of adjustment I threatened just to chuck it all and head for Windows XP, a move virtually all of my friends would have applauded if for no other reason than to shut me up about the things Apple did "wrong" in designing and deploying an operating system they don't care about one whit.

My own experience of migrating from OS 9 to OS X seems to have been more straightforward than Dan's experience. Amongst the few OS 9 apps that I haven't managed to replace are MS Office and Nestcape Communicator so I'm trying to use these as little as possible. I know there's an issue with the Umax 2200 scanner I have as there aren't and OS X drivers for that. But all the apps I use on a day by day basis are running natively under OS X. It has been rock solid ever since the changeover. The only (non-beta) app that consistently misbehaves is IE 5.1.3. Go figure!

Incidentally Dan found tips for migrating an OS 9 Radio installation to OS X useful which certainly makes documenting it worthwhile.