I'm in the market for a new laptop and I am dead set on a mac. I'm a junior Electrical Engineering student and want to go back to apple. I have a mac from high school, but I thought PC would be better for engineering when I go to college. After using an alienware m11x for 2 years, im ready to jump back. I dusted off my 2006 macbook pro ag 15" a few weeks back and I fell back in love. Now that you know my story, I need an opinion from both 13" and 15" users. I would get a new 15" and maybe retina if i had the cash, but I'm on a pretty tight budget. My question is, would it be better to get an older (2011 maybe) 15" or a 2012 13" and upgrade with ssd? If im going 15" i would want the hi-res to take advantage of the extra space, but it might be hard to find for the right price. Portability is not huge issue between the two, but its a tiny plus for the 13". I'm fairly aware of the types of programs I need to run and it shouldnt be an issue for either machine. thanks for the help and glad to be back!