You guys think keeping it at fhd kills less battery?
Decent. Was initially worried because it was no where near my Note 9 or OnePlus 6T. It's a little bit better than the regular S9 was. It'll get you through the day sometimes, other times you will need a refill.
All-in-all, after owning the Plus for all of one evening I decided the extra battery life wasn't worth how easy and elegant one-hand use felt and looked on the regular S10.
How you perceive battery life may depend a lot on which phone you're coming from.