All of my knowledge of Ace and Seven currently comes from the audios, which are really wonderful. What's amazing is that Sophie Aldred sounds nearly exactly the same in the audios as she did in the series! It's uncanny! I mean, you listen to the eps with Five, Peri, Nyssa, or Tegan, and they just sound older (even Seven to some extent), but not Ace. Actually she really holds her own against Seven in the audios even more so than what I saw in Fenric, because I think she's portrayed as more of an adult than a child. Still has the tough destructive streak, but there is less of the Doctor telling her what to do, if that makes sense.

Anyway, yeah, this one might bear some re-watching but I got it via streaming, so it's actually not that straightforward to re-watch it piecemeal without getting the discs. I might take your advice and get my hands on the novelization.