Upon reflection, some of the problems I had with the fighter in my game arose from the fact that the DW fighter seems most like the D&D/Pathfinder fighter. Interactions with other players, even in the midst of battle, stayed more rooted in the fiction, but I kept falling into just trading blows with the fighter.
The DW druid, in contrast, and the Mage, are so different that it was easier to exploit all the goodness of the rules. I think I’ll go have a look at #fighterweek for ideas. If anyone has specific pointers, I’d love to hear them.