Apple's solution
There's been a rise in Mac sales recently and with that also new users of OS X. So I think it's important for people to know what their choices are in this matter. Not hereby saying that I have the solution. The OS X installer has it.
After reading(searching Google first) Apple's page on upgrading to Tiger I found that I will probably be changing my mentality on the installation issue.
I used to Erase & Install on each new major release of OS X, from 10.2 to 10.4(PPC and Intel). I came from AmigaOS where there were no Upgrade option(no need to re-install at all though) and next with Windows where it was the law that you reformatted on each install.
Anyways, I'll be doing an Upgrade with Leopard. I'll copy my home folder and all the other little things over onto my external harddrive for the just-in-case scenario.
I have altered some things in the CoreServices folder and changed all my icons with CandyBar. I basically want those things to be default but at the same time have all the apps and frameworks overwritten with new ones. f.ex the DuctTape.framework that PithHelmet installs..I want that gone upon Upgrading. Small things you might think, but essential for me.
I think that it's a matter of letting go of old mentalities. If you Erase&Install you must have a backup already, so why not try the Upgrade option!? I will.
But but, if I have nothing better to do I might Erase&Install anyway, haha
I'm very ambivalent.
I must say, you all have good points. I'm making another one. And so will someone else.
Here's the page.
http://www.apple.com/macosx/upgrade/