I've got a Macbook Pro Retina 15" and I have a Moshi hardshell case for it. The case is awesome - great fit, thin, light, great protection. Lately though, I found that my Internet gets really slow after using the computer for a while. I took it in and the service guy suggested overheating might be causing it. Initially, I didn't believe him. Sure enough though, I got home and began having the same issues. This time, I noticed the computer was indeed getting very hot. So, I took off my case, held my laptop in front of my AC, and voila! problem solved. As I took off the case, I also noticed that there was a lot of heat trapped between the case and the underside of the computer So, love my case, but can't use it due to overheating.