I bought my first Apple computer on 2/17/2001. The wait for my copy of OS X 10.0 on 3/24/2001 was
painful. I didn't use OS 9 once I had OS X installed. Guess I was lucky that I didn't have legacy software to worry about and could start fresh just like Apple was.
For the first few months, all I really needed was the WiFi card, Office v.X, Xcode and gcc at the command line so I wasn't hurting for applications like the Photoshop crowd.