Realistic animations or not don't matter to me so much as that there is a fluidity to them. If I'm going to spend thousands of hours with this character, its movements need to feel smooth and natural from one to the next. There is nothing that turns me off an RPG more than character animations that feel janky and disconnected.
Realistic combat animations are important to me. It looks really weird when a char swings a 30 kg two-handed hammer like it would have no weight. So i expect a very slow attack speed with that hammer. And if the hit lands then it should look like a hit with a huge and heavy hammer. :) Just imagine: everything has innertia.
Cheers