REALLY newb question: does radio upgrade to 3.42.30 help data speed/latency?

[GoldenTiger]

I'm in the northeastern US (CT) and was wondering, does upgrading my radio from the stock XV6800 1.xx that I had, to the now-loaded 3.42.30 do anything but let me use GPS, or does it improve data speeds/latency as well (I heard something about EVDO Rev. A in the radio chat threads but nothing concrete)? Thanks! I'm noticing seemingly quicker load times but I'm not sure if it's a placebo effect.

[GoldenTiger]

One other question, is there a way to check if I'm connected Rev. A or Rev. 0?