My battery life is amazing also.
I have always disabled the wrist turn-on action in the past as it absolutely DESTROYED my battery life (the damn thing would go dead in like 5 hours). I hated to turn it off however because it is just so darn handy and I don't want to wear out the tiny hardware button.
With Null 20/21 I have been experimenting with different combinations for battery life. I could care less about bragging that my battery lasts 4 days etc. with all the features turned off, but I do need it to make it through a 12 hour work day before it dies.
For the last two days, I have left the motion on and the only thing I have done to increase life is leave the top clock speed set to 1200 with both cores enabled (on demand governor) and it has made it through both days with still a little spark left.
This was with blu-tooth tethering connected all day also with gmail/weather syncing (even though I could certainly live without that).