Funny that 8.1 seemed to resolve a similar issue for my ThinkPad Tablet2 at work but the battery life issue is there with Bluetooth off and somewhat even without adjusting the BT setting. Battery life overall seems negatively impacted, but you know something, I couldn't care less. 8.1 seems to me to be proof that Microsoft is FINALLY 'getting it' and that makes the battery issues, which they have already acknowledged as being targeted for resolution in the live 8.1 drop, really not bother me at all.
ThinkPad Tablet2's (several at work) had been refusing to Wake from connected standby at all. Add FortiClient to the unit, v4.02 (I know, I know. I did not choose this solution) and the no wake from sleep(CS) changed to a crash requiring power button-voodoo-mojo-magic to get the machine to come on again. I am seriously talking about holding it down once the EXACT right amount of 4 to 6 seconds, releasing and then touching it Exactly the right amount of regular 'on' duration to get the little green light to appear below the front facing camera and lift-off! Man was this ever annoying. I seem to remember the head of Intel and Ballmer playing the blame game on this one about this time last year. Either way, SO FAR, so good with that issue. We thought we saw this again recently with my co-workers new tablet and I was worried for a minute but it was just him having let the battery die. I was so glad to see the bios power warning when I tossed it in my dock.
The new 8.1 gives me a level confidence with the tablets that I have not had before with this Windows8 or any of the 3 devices I have owned and used as production machines so far. Having Staged 15 or so of these tablets for a pilot program and seeing each of them display the exact same behavior I was beginning to lose faith in Windows 8 tablets. We had 3 Surface RT's in for testing, I owned my own private RT and then later a Surface Pro. All of my experiences with the devices and the Original release of Windows 8 was negative. No one in our group at work even wanted to look at the RT. I gave my RT to a co-worker who is normally a gadget fiend, he has not even mentioned it since. The pilot involves equal numbers of iPad 4's and ThinkPad Tablet2 devices. I am soley responsible for the support of all of them and to date have recorded 5 requests, all to reset passwords on the Tablet 2's. This would indicate the most of the pilot users are simply not using the Windows devices. At some point soon, the Ipad and Windows device groups will be ordered to swap devices. I just hope that 8.1 will have dropped live by that time so I can restage them and feel a little better about actually supporting these devices in the field, as tools, not toys. We never hear any complaints from the iPad 4 group but I am guessing that's because people don't care that much if they are actually a tool or not and just use them even if not for work purposes.