@DocAaron: you did not replace only your battery, did you? Maybe your replacement got parts from another batch of chips that interact differntly with software or are defective?
I can now (for my phone) confirm what I reported earlier: I get the battery drain and usage time problem as soon as I enable "mobile data" - the problem even stays when I switch mobile data off later and goes only away when I do a "reset network settings" - now, explain that with a defective battery.
The odd thing is, this battery drain happens after enabling mobile data despite the phone being in the house with perfect WiFi connection at all times, so it should not even need to use the mobile data (not to mention the fact that basically everything that could transmit data is currently disabled).
I would love to hear from others who have the problem and are in an WiFi environment:
If you do a Network Settings Reset (which should leave you with no WiFi and no mobile Data):
* is you battery drain gone (and the increase in usage time while on Standby)
* is your problem still gone when you re-enable WiFi
* is the problem back when you re-enable mobile data
* is the problem then still persistent if you disable mobile data again, until you do another reset of Network Settings?