When the iMacs first came out my school got them, and it occured alot... OS9 was horrible compared to OSX... I would even say it is the equivalent of Windows 98
I used Windows 98 and OS 9 at the same time (on different computers of course).
I found OS 9 to crash all the time, and hated that it never multi-tasked right. I found that background operations always stopped when I switched a different program to the foreground. For example, websites loading in my browser would stop loading if I switched to AppleWorks.
So, I had to wait for tasks to complete before switching to another Application. Otherwise, I'd have to switch back to the other Application and wait (or else restart the process over again if it timed-out).
OS 9 was much better than 8.6 in those respects. But, it was still a royal pain.
I would actually equate OS 9 and older versions to Windows 3.0 (yes 3.0 not 3.1). Well, O.K., I'll give it some credit, I'll be generous and call the final OS 9.2.2 release comparable to Windows 3.1.
OS X is definitely a much better environment. Switching to OS X was probably the best thing Apple ever did. It took away all my complaints (though it added a few new ones which I've resolved with the purchase of 3rd-party programs).