I currently own a 15" Core Duo MacBook Pro from early 2006, and I'm looking to replace my machine with either an MBA of MPB this coming February. More specifically, I am deciding between the 13" MBA and 13" cMBP. At first I was more interested in the Air but I'm not so sure after seeing its internal build. After looking at the iFixit breakdown guides for the retina MBPs and the Air models, I find that I'm not to fond of the over-use of proprietary components that can't be easily or cheaply replaced. One of the reasons my current machine still runs is because I was able to replace the HD, battery, and Airport card myself, and upgrade the memory. I don't purchase new computers that often so I like to get as much as possible out of a machine. With that said, how does the current serviceability of the cMBP compare with earlier pre-unibody MBPs?