ou'll want to first take a look at upgrading and run a pilot before doing so. 2003 is a *very* different product than 2001 and one of your largest problems will be unlearning 2001 to learn 2003.
For all practical purposes, 2003 is a 1.0 product because of all the changes and porting to the SQL database. IMHO, you'll need to get some education on 2003 and then run a pilot and then decide if upgrading is correct or not.