Wireless carriers all offer what they call unlimited data plans, however once you read the fine print, you realize that not one plan includes truly unlimited data. Instead, each carrier and MVNO practice what they call deprioritization, that is, once you go over a certain amount of high speed data in a month, your speeds may be temporarily slowed during times that the network has a lot of traffic. Each carrier and MVNO thus offers a different high speed data threshold that data deprioritization takes place at. On AT&T and Verizon that number is 22 GB, Sprint's number is 23 GB while T-Mobile leads the pack with 32 GB of high speed data available before the deprioritization policy gets applied.
Today it has leaked out that T-Mobile will be increasing the amount of high speed data included with its unlimited data plans to a whopping 50 GB before deprioritization occurs. This means that T-Mobile customers will get more than double the amount of high speed data included with their plans than they would from any other carrier. The change is set to take place on September 20th, and at this time there is no word if higher amounts of full speed mobile hotspot will also be included with select plans.
T-Mobile's ONE Plus plan already includes unlimited LTE mobile hotspot, however LTE speeds may be purposely slower when you are using your phone as a mobile hotspot as opposed to when you are not. Perhaps this will now change too.
At this time there has not been any response from any of the other major wireless carriers in response to T-Mobile's new policy. It is likely that they'll all have to respond in some way though, probably by increasing their own high speed data thresholds.