LTE is nothing new, it's been out for a while. That doesn't matter, as pretty soon a lot of new iPad owners are going to dip their toes in the 4G/LTE pool for the first time. It will be as fast and amazing as it always is for those making the jump from slow 3G to lightning fast LTE. That means before long we will start hearing from those new iPad owners who are regularly crashing up against the LTE data caps the carriers have in place, and it's not going to be pretty.
The Android smartphone world is well versed in the benefits of LTE, as phones have been shipping with that capability for a while. Having broadband speeds in your pocket is a heady thing, but you quickly learn to pay close attention to how you use it lest you butt up against the data cap early in the billing cycle.
Keeping an eye on usage is not that hard for a phone, as the small display limits how it can be used anyway. That's not the case for the iPad, a device that is designed for content consumption. I'll bet we see new iPad owners streaming hi-res video to take advantage of that Retina Display, only to discover that the LTE data well has run dry in a hurry. What are they going to do then turn off the LTE plan, or pay $10 per extra GB? It's going to be fun to watch.