I don't know about being limited with OS 9. I use it all the time on my Lombard with 9.2 and Wamcom Mozilla, with a wireless card. I find it was much more limiting to be on dialup rather than DSL, than the Lombard versus the iMac G5 with Tiger. I have not found 9 to be buggy or prone to locking up at all, and I like it because I can use my Airport to run the wireless card. In X it won't work without a driver that costs money. I even have the older versions of iTunes and iMovie in case I want to use them.

And if there is anything you haven't been able to do because Classic won't run it, then you have 9 for that. Or, partition it and made it dual-boot! Then you can really compare. ;D