Also, going back to the original discussion (before screen qualities were brought up) between a 13" Air or 13" Pro, I had both (Core i5 2011 versions). While the 13" Air was awesome for portability, I guess I'm old-school and like having the option to open up my laptop to upgrade parts. I had the 4GB/128GB version so would be stuck at that forever (unless I bought 3rd-party OWC SSDs for a price premium). Ultimately, I like having 8GB minimum nowadays and the extra 0.7GHz processor may help (along with 8GB RAM) would theoretically allow me to run more VMs should I need to in Parallels or VMWare Fusion. I also just like having "max power" so I have some reserves in case I decide to open 70+ tabs in Firefox or whatever (I actually do this often, I need to review my workflow lol).
I upgraded my 13" MBP with 8GB RAM and 256GB SSD and get basically the same "snappiness" feel of the 13" MBA stock. Its pretty great and I don't mind the extra 1.5lbs or so.