I like the question mark motif too.
Anyways, I just watched Dragonfire last night.
I quite liked it. My favorite of McCoy's era so far (I'm watching them in order, for the first time as well). It was fun to see the introduction of Ace; and the exit of Mel (though it did feel a tad sudden, there was literally no build up to it).
Much has been made of the silly "cliffhanger" at the end of the first episode, and it is silly, but it certainly didn't ruin my enjoyment of the story.