[jameswyse]

I do similar work so I guess I can chime in with my experience here.

I went from a 2011 13" MBA to an early-2013 15" rMBP and found the difference to be massive. The main benefits being the incredible display and a pretty decent cpu/gpu/ram upgrade. After using the retina for a couple of weeks I opened my MBA (which was gathering dust on a shelf) and couldn't believe how bad the screen looked in comparison.

However I do miss the battery life and boy does this thing get HOT. It's summer here in Brisbane and yesterday (it was around 35c) my CPU got to 106c.. my lap did not enjoy.

But yeah I definitely recommend the retina. Be sure to max out the RAM too.

Edit:

I recently added a 27" haswell iMac to my collection which was another massive improvement. I've been doing maintenance on an old node.js app that has a pretty crazy build process and compared the runtime on each of the machines - The MBA took just over 3 minutes, the rMBP about 1.5 minutes and the iMac did it in under 20 seconds! I still spend most of my time on the MBP though :)

[cabbeer]

It's not a good idea to use a laptop in your lap for extended periods of time... expecially if it's running at 106C... especially if you're a male.