I realize this may be a slightly petty question, but it is a $200 one to me. I'm entering college this fall and have decided on the MBP line of laptops. I've got it narrowed down to the upper level 13" or the lower level 15". I've played around with both at best buy and for short amounts of time the 13" screen seems good and gives me an extra bit of portability. But I'll be spending long periods looking at the screen next year. Does anyone with the 13" experience eyestrain or fatigue after looking at it a while? Or should I shell out the extra cash and get the 15"? Thanks in advance