If you look at the comments on the article, you get an idea of how bad it is. The Nexus 4 was intentionally made without LTE so that it would be an international phone. Most areas, worldwide, do not have LTE and, in those places where they do, the frequency used for LTE varies widely between carriers -- making it near impossible to add international LTE to a phone.
As others mentioned, HSPA+42 in the real world approaches or exceeds the speeds users are averaging on LTE. For an example, in PC Magazine's test for the Fastest Mobile Network
, shows that T-Mobile's 3G (which for those cities is actually HSPA+ 42) typically averages in the same range as carriers using LTE, and in some cities their average speed is faster.
Last, since this thread is about the Nexus 4 on T-Mobile, it doesn't matter in the least that the Nexus 4 doesn't have LTE, as T-Mobile does not yet have LTE, either.