Always a clean install. Always.
Whether it's NT4 or Win95 or Classic Mac or Snow Leopard or Mavericks ... always, always do a wipe and a clean install.
Life is too short to deal with the alternative.
It's potentially contradictory: the alternative is upgrading your OS and find pretty much everything where you left it, instead of having to reinstall everything. I.e. life is too short to spend time reinstalling everything.
Surely, it's an opportunity to do some cleanup of unused stuff, but otherwise, I haven't had a lot of problems upgrading OS X. (nothing memorable at least)
I've had 2 or 3 issues where old config was the root cause, but those are few and far between. I might be an outlier, but it's always just "worked for me".
Edit: oops!
Of course, you meant OS 10.2 (a.k.a. Jaguar). Otherwise, it's not that impressive ;-)