My wife has the MBP with Retina Display. It's got lots more pixels than my MBA, but no more real estate. Display widgets can really only get so small while still remaining useful, and increasing pixel count involves some tradeoffs with things like power consumption.

I could have had a lot more vertical real estate, but I decided that since I'd be carrying the thing around in my satchel, physical size was also a consideration. At home I can plug it into a monitor that's much, much bigger.