I don't think awake time is a good indicator of battery usage -- at least it's not in my case.
My awake time used to hang in the 10-14% range. About 3 or 4 weeks ago, I installed Good Technologies Exchange Cliient and ever since then, my awake time has been 100%. If there's been any change in battery life, it's been too small to notice.
In a typical day, I still use 65 to 75% of the battery charge between 7:30 am and 5:30 am when I put it on the charger for 2 hours. That's the same performance I was getting back when the awake time was in the low teens.