I am going to upgrade a friends iBook from 10.2.8 to Panther. Normally, on my own system, I always do a clean install, just because it feels better and I have all my application CD's at hand anyway. But in this case, there are a lot of applications installed, Adobe stuff, Classic environment and lots of other things. Not all CD's are at hand. Assuming upgrading with keeping user documents an applications is possible (it is, isn't it?), what is the chance of problems with the upgrade procedure or with applications afterwards? What are your experiences?