What they got right: I was so happy to see Matthew and Emily were indeed going to be companions, and Lee's kept their data handy. Both characters are in keeping with how they were when we last saw them, including Emily, who references her changing in the first arc of the ongoing. The character models match as well, but since the artist for that arc, Al Davidson, is back in charge, that's not surprising. We get looks at the old control rooms and wall styles, and Davidson did his homework, even using the brickface areas that showed up in the show before (probably budget issues, and I wish I remembered which Tom Baker episode it was off the top of my head). We also get a bit of mystery (at least for me, as I haven't watched the new series in a while) when Emily reaches for a gun (Lella revisited?) and the Doctor tells her why she can't have it. Makes me curious. Also, the villain of the last arc is back and a great foil for the Doctor.
But what I really like, and it deserves its own paragraph, is that this story is set in the TARDIS. I enjoy those stories, as the TARDIS is sometimes a bigger mystery than the Doctor himself. In fact, if you were to ask me which classic Who episodes are must sees, "The Edge of Destruction" is high on the list partly because of how it gave us a glimpse into the nature of the ship (but mostly because of the characters), and the TARDIS was only depicted with two or three rooms at the time. Continuity porn is really done right in this issue, both visually as well as in the dialog. (Check the scene in the beginning, where the Doctor is wearing various bits of his old costumes.)
What they got wrong: Emily's shirt and pants don't match? Really, there's not much negative here.
Recommendation: This could end up being the best IDW Who story yet, or a major letdown. Prior experience with this team, however, leads me to believe the former.