My experience with Apple laptops is as follows:
13" original MacBook (2006) - 15" MacBook Pro (2010) - 11" Macbook Air (2011) - 13" rMBP (2012)
I loved my original macbook, it lasted me through college and is still running for one of my friends today. The 15" Pro was awesome, I loved the power but just didn't like lugging it around, so I moved to the opposite end of the spectrum. The 11" Air was great - but performance was a bit lacking on a 1.6Ghz ULV i5 and after a while the screen space was just too cramped. That and the fans where quite obnoxious and liked to start up often with my workload.
The 13" rMBP is honestly the perfect machine for me. Fast enough, quiet fans that rarely spin past 3000 RPM, but it doesn't even matter because you can't hear them. The screen is phenomenal - mainly because I can switch from 1280x800 which is great for just reading articles on the couch all the way to 1680x1050 (Same res as my antiglare 15") when I am getting work done.
I was considering the 13" Air for a while, but the price drop for the rMBP put me over the edge (Plus buying refurb 2.5Ghz + 256GB SSD) and I am glad I did, as this is nearly the ideal laptop in my opinion.