I played a fair amount of the original Warhammer Fantasy RPG, and was excited to pick up the 4e rules. My excitement abated, once I reached the combat rules section. The new Advantage and degree of success and failure rules sealed the fate of me ever running the system.

It strikes me as so cumbersome, at the point of play, that I do not think I will ever feel comfortable running it. The original ruleset works fine though...so you can always try that, if you are interested.