I'd not mind if the iPhone 5 was twice as thick as the iPhone 4 if...
I wouldn't mind if the iPhone 5 was twice as thick as the iPhone 4 if that meant:
1) LTE (that could be switched on or off) implemented with something similar to a Qualcomm Gobi chip that worked with every CDMA, GSM, and 3G frequency everywhere in the world (such a chip actually does exist).
2) Much longer battery life when in 3G mode, and battery life similar to the iPhone 4 when in LTE mode.
3) Standard-size SIM card (aka "mini-SIM," which is the global standard that the original iPhone, iPhone 3G, and iPhone 3GS used) instead of the inconvenient micro-SIM that the iPhone 4 uses. This would make things much easier for people who buy a factory unlocked iPhone 5 and travel internationally.