I bought a 13'' MBP 2 years ago, it had 150GB when new, and when I upgraded to Lion everything seemed perfect, 4 months after I upgraded (3 weeks ago) my mac started crashing constantly until it froze in the initial white screen with the apple logo and would not go on. I had to take it for a reset and now I have snow leopard again, as before. The guy that ''fixed'' it said it was because Lion needed much more capacity than 100gb and it slowed my mac down...he was not an apple technician since there's not a genius bar in my town, so I don't know if it's true. It doesn't seem right that I won't be able to upgrade to future OS X... Is it true? Should I install it now that I have full 150GB and buy an external hard drive? Thanks for your help!