Bob, yes possibly for OSX, however there are numerous users who are happy. With extra RAM and more HD space, your machine should be stable, but the bus speed and limited vRAM will be more noticeable in OSX than in OS9. As a general comment, the G4 processor does deal with OSX far better than the G3. The vast majority of improvements in OS9 past 9.1 are related to its compatibility with classic, however most machines that I have used, seem to run 9.21 or 9.22 as well or better than 9.1
best wishes
Andrew Platt