2h 9m 47s on screen, 29m voice calls (don't talk on the phone much, clearly... :))
And a fair amount of google voice/sms, a bunch of email, a little web stuff. All on 4g, with bg sync on.
Like I said, nothing scientific, but battery life seems to better, or at least good, if anything.
Today, with KL2 back, its been with 1h32m calls, and 2h 15m display on to get from 100 to 35.
Same location, everything same. BG data on, 4 sync accounts, everything same, except modems.