hopefully someone else chimes in as I'm certainly no expert, but that seems about right to me. You're on pace for ~4.5 hours of screen time which is basically what I generally get. I'm sure some others might get more, but I THINK that is normal. Gotta remember, you have a bigger screen and a faster CPU now than your old phone....can't expect Prius gas mileage when you are driving a Lambo.
Again, that is just my opinion based on my own phone, others will speak up soon I'm sure.