I won’t recommend doing it unless you’re sure your area has LTE available anytime. As I rarely use mobile data and anyway my city is all covered up in LTE, I’ll try it.
Edit: making calls didn’t work with “LTE only” selected in my area. Might not be your case, though.
The drop in battery life was obvious to me. I bought recently a new battery and was having an outstanding battery life in 14.1. In 15.1, it foresees only 13 hours with 88%. And I barely used it today…