Hi! I am looking for an update. I have used mac since i was old enough to tell my parents I don't like windows. I am graduate student and will start working on computational biology. I was user of macbooks, then my current macbook air (1,3 GHz Intel Core i5 with 4GB RAM). Doing regular biology and stuff this was portable and powerful enough for basically everything. But since I started this biocomputer thing it's always running at full. Becoming very warm in the process and my RAM is simply not enough. So... I am considering moving to the pro. Being used to the portability of the air I considered the 13" one. HOWEVER. This would be my ONLY computer. I move... A lot. Among countries and continents. In time periods that go from a couple of months to a couple of yeas. So... big fancy Desktop is not nice to have and move as often. For this I considered the 15 inch as better. Since I don't make enough money to pay for the discrete GPU it would be only for the quad core vs dual core and maybe the iris pro vs the HD6100 of the 13 inch (considering I would go for 16GB RAM on both, not making THAT mistake again) Is the price different worth it? Or should I favor portability? Or should I keep my computer and try to ssh my way through all of this? Thanks, and sorry for long post.