I’d buy it, but two things keep me from doing it: the massive 4.7-inch display and the lack of LTE. The display of the iPhone 5 is really on the edge of what I find pleasurable. Everything larger is just too big and not ‘mobile’ anymore. I can’t stand that trend of making displays of smartphones bigger and bigger.
I’m using LTE on my iPhone 5 wherever it’s available. It’s fantastic, 3G feels like EDGE now. Therefore the Nexus 4 would be a downgrade.