Unless money is a huge concern, I would go with the macbook Pro. For me, the screen on a macbook is entirely too small...use both for a week and you would realize how nice it is to have the larger screen to work with. Also in my opinion, the keyboard on the macbooks are terrible. They are like toy keys. The keyboard on the macbook pro is perfect in my opinion...and man is it nice when im working in a low light setting for it to automatically illuminate for me. I don't think the 15" is too big for portability either...but I would say the 17" probably is.
It comes down to personal preference...but that's just my opinion. If you have the money, get the pro, if not, consider the macbook.