
The scaling.
I was thinking it would run at the native resolution. I knew they were making double-density icons and do forth, but I hadn't put two and two together. I didn't appreciate that the screen would have the same real-estate as a 1440 x 900 screen while in "Retina" mode. Of course, thinking about it for more than a few seconds, it's obvious.
It's good that you can run it in other resolutions. Lots of times I want more real estate to minimizing paging and scrolling.
Cheers,
Scott.