Which do you use? Which do you prefer?

I plan on starting up Skyrim again in the New Year after the next expansion and I am looking into utilizing a combat mod and I am torn about which one to go for. They both seem interesting.

In terms of features, very few combat mods apart from Duke's have any real features. But it might be less accessible and a lot of people don't care what is going on in the background as long as it's fun, you should try both to see which is more fun for you.

Duke's is my number 1 must have mod for skyrim so... Some of my favorite features: dynamic stamina burn for all attacks, weapon reach based on 3d model (very important for me), momentum and locational damage, pain reactions (hurt them enough and they'll stagger) attack blocks, npcs fumble (can hit each other) and feints.

EDIT: I forgot Smash of the Titans. Big actors can knock you around. He's got an extensive readme if you want to learn more.

Duke Patrick's is made by a professional in the SCA combat sport and is much more realistic than duel. It will require more tactics and will be much harder however.
Choose duel if you think it's too hard, I myself prefer Duke Patrick's mod.