If you were to go off rumor. If you give your phone a full charge the first initial time then the battery should have a better/longer lifetime.
Last's longer with a full charge
Might last you 6 months longer
I know that applied for old old old phone batteries, but now-a-day's I'm almost positive it doesn't have all that much merit in it.
Given it doesn't really matter, you're going to have to replace it in about 2 years or so, and that's if you still have the same phone.