The com rom nor the patch include a radio..you'll be on whatever radio you had when you flashed the com rom..(you can check this in settings-about phone-baseband version (blah blah blah..EDO1, EB01, DL09, etc etc)
I OTA'd to get to the ED01 radio and can't say there is a major difference between it and EC01 radio..I don't use navigation or gps much, but when I have it works well. EC01 I would say is just fine..and much easier to get..
The battery for me is still tangible as I am using my phone much more than normal. Still getting things put back together after data wipe/factory reset..
In a day or two I'll go back to normal use and be able to judge the battey a little better.. until then I can't say the ED01 radio is draining the battery less.
hope that helps