How does the heat output compare between the Macbook Pro and the Macbook 12"? for hear, noise, typing, and performance? My 13" Macbook Pro is easy to do web development on and very portable, but it burns my lap after working for 30 minutes. I'm stuck working that way sometimes when the conference table in the meeting room s full and I have to worm from a chair off along with the wall. I have a personal 15" Macbook Pro that works great but it's too bulky to carry around the airport when I travel on flights. I'm looking at laptops because I cannot do ruby on rails development on my iPad Air. I'm open to older models and returns as long as the laptop gets the job done.