My problem too is that I have it set for 6 hr updates but it seems to continuously update several times each hour. I think this is why it was draining my battery so much. I'm not sure.
There's no question that it had a negative impact on my battery at first. I installed it in the evening, with the phone on the charger at 100%. I went to bed at midnight, taking the phone off the charger. When I got up at 7am, the battery had dropped all the way to 70%. Normally, I see it drop to 90% for that same time period.
I suspect it's still dropping faster than before, but with the location feature turned off, it's within acceptable levels for me.