I'm surprised that this thread is here, or is a surprise to anyone...
For the sole reason that underneath the Double Tap to Wake option is the note:
"This reduces battery life"
hence I'm surprised why people are surprised when they find it reduces battery life! :grin: :grin: :grin:
Great, except in my experience stuff works like this (experience with glance (peek) and double tap to wake on 920 and 1020):
1. 920 drains less battery when using just glance (wtf?) (both without sim cards)
2. 1020 drains noticeably more battery with double-tap to wake than 920 does. Like "If-I-have-this-on-I-cannot-use-my-phone-for-a-long-day-without-charging-it" with what I would call light usage (web browsing (wifi) and occasional calls/text.
3. 920 does not experience anything near the crazy drop the 1020 does with "double-tap to wake" turned on.
The surprise isn't that is uses more, the surprise is that it takes so much, and varies so much between devices. (note: why does glance use less for me on a 920 than 1020?!?! AMOLED should win here)