So the iPhone 5 on AT&T can't use LTE outside of the US because AT&T uses some LTE band nobody else uses. Bit of a bummer, but I wouldn't call it crippled since you can still use 3G voice and data pretty much anywhere in the world. International roaming is actually one of AT&T's few strengths. I'd be more upset if International data wasn't so expensive. At $300 / GB, turning LTE on overseas would just scare me. Hopefully they'll come out with a unified chipset in the future and prices for international data will go down.