I'm not as comfortable with the combat as I was with previous games, but I'm hoping it'll feel more fluid as I play more. I really miss having R1 as an option for countering.
Completely agree with what others are saying though, it has a very natural feel to it. I just wish I didn't see all the bugs where either I or the AI gets stuck and have to start over from last checkpoint. I loved the use of the snowstorm for cover. Felt very Splinter Cell like in the mission where you eavesdrop on Washington.
I'm a few hours in and am at the Expedition mission where you're working with the Natives to take the general out in Sequence 3.