What version of the Radio firmware are you running, and are you verizon or sprint?
It's *not* the 3.3 rom, because if it were, everyone would have this problem. My battery life is actually better under 3.3 vs 2.2 vs 2.0 Sprint.
It could be 3.3 w/ specific radio firmwares, or 3.3 on specific revs of the 6700, or carriers, or phases of the moon, or whatever. But it's not a blanket 3.3 issue - not unlinke the disappearing SDCard
Let us know how it goes w/2.2, and if you can post the radio firmware rev, and which carrier you are using.
EVDO active 100% of the time can only happen if something is sending data 100% of the time, or just often enough to keep it alive (which is fairly often, like every minute or so) - that would keep CPU running higher that 100mhz, and keep the radio powered up, and that yields horrible battery life. But something has to be running for that to happen, or your radio firmware is interacting badly with the OS...