A warder should have Inhuman Toughness (catch being the One Power) and a True Strike equivalent - they are considerably more resilient and better at combat than they were before the bond. However, they also got Senses 1, which reflects their tie to their AS, and a +1 rebate for the obedience and their life being in their hands. For the AS, the bond is actually a spell effect, albeit a permanent one.
So effectively, the Warder Bond is a fairly powerful Transformation spell that gives permanent powers. If the bonded guy has no refresh open to pay for its 2 refresh total cost, they have no free will at all, being just extensions of their AS. (except the AS are not supposed to use it for that). If they do have refresh left, they are not pawns and they can resist it - though the AS shold be able to more easily control them with further bindings like Moiraine did with Lan. (treat this as their high concept)