As a subscriber to Verizon's 4G LTE service using a USB card, I would be peeved to find out that smartphone users have access to the same network with no data consumption limits at half the cost.
I will also second what @otacon72 said. 3G or 3.5G is good; WiMax 4G is much better; LTE 4G is the best (by a substantial margin). Unfortunately, when using LTE, I easily consumed 1 GB of data in under 90 minutes. As you can imagine, it wouldn't be hard to blow through a 5 or 10 GB per month data consumption limit, which does make the slower, cheaper, and unlimited WiMax options a lot more attractive.