Snow Leopard, upgrade or fresh install? Whass the difference?

[roadbloc]

As stated. Whats the difference between fresh installing and upgrading (apart from the obvious that you'll loose all your files and stuff on a fresh install).

What i mean is, is there any difference with the OS depending on your choice?

 

[GoCubsGo]

Some are reporting a fresh install has been running better. It was the case for me on two of three machines.