Depending on the faction you lean on Khorne are extemely set in my opinion to be some of the best in the game!
Supplimented with Tzeentch magic I'd say they are a good force to reckon with. I like the nurgle stuff too but I'm khorne all the way
Khorne is not as strategically fit cause your doing one thing and one thing only Close combat.
I really like getting the greater Demons too lots of fun...
We should play soon, perhaps the next stop at acme?