I live in the middle of nowhere, generally get midrange voice, 3G, and occasional 4G. It's largely a crapshoot if I get 4G at all but when I do, the signal is pretty good (don't ask how I haven't the slightest idea)
That all said, the radios don't seem to have done much for my signal or speeds but they do seem to have much better WiFi/3G/4G handoff. It's not perfect, but it definitely feels improved. The tradeoff for this is that it seems to be holding onto weak signals longer, which likely where people are losing battery.