I'm not doing a factory reset on my phone, either. I just periodically plug in on the bad days. I'm saving a factory reset for when (if?) my phone gets lollipop (again, I have a Droid Maxx, and an upgrade this August, so I may have another phone by the time Moto/VZW get around to the update.)
Like you, I have days where Google Services is acting fine, as it was yesterday (it was sixth in the battery list at only 5%.) Today? Fourth at 10%.
I've read others point the finger at Google Calendar. I do use Sunrise calendar these days, I may choose to turn off calendar sync in my account in settings / google just to see what happens. (I don't know if that will affect Google Now, though, and its ability to tell me when to leave for an appointment. Well, I will test that, too.)
I've also switched to the InBox app for email, which does seem to use more battery, but I turned off sync to the Gmail app at the same time to minimize the effect.