I think the only advantage of full LTE speed is with high bandwidth video, and with such low data caps, high bandwidth video is a poor appication for this data, because it eats into your data cap so quickly. You will be still using LTE data with the 3 speeds, with the same latency advantages as LTE, albiet throttled. I am told it is throttled at around 3.5 mbit/s, which is more than sufficient for most cases.
