Agree with it all except the battles.
I am playing the Native Expansion, so it might be different, but anytime Im in a battle with a computer, they just all charge. No line, no archery barrage, no specially timed charge. Just run and die and chop. I mean its fun to defend against, but taking the time to actually strategize sometimes feels pointless.
For me, its just the overall depth. It's a bit like Skyrim, but everything is deeper, more customizable, and the combat is supreme. You get the big open world, but with it comes a constant pressure to make the right decisions. I like that.
Also, the whole idea of building up an army is just awesome. So customizable.