how hard is it to change the mbp's HD if i do decide to keep mine?
If you are comfortable taking apart laptops, it is a pretty easy upgrade.
see thats what was nice about my compaq i had, it had a little door and was extreamly easy to just pull the door off, and pop out a few screws, ive taken my G5 apart many times, but never the top off of a laptop, so if thats what its going to require, i might have to think about that one.