Cons:
The biggest con I have here is... well, if Guillermo was going to be made back into a human at the end of the season, I wish we'd gotten to see more of vampire Guillermo. I actually don't mind narratively this turn where he goes back to being human, but why couldn't we see a whole season of him getting to be a bat and go flying and do all the other vampire things, in full-swing? That way the fact that he's not ready would hit a little harder: he can't bring himself to drink human blood, which is the only way he can continue to be a vampire, even though he's experienced all the perks. I just think that would have been a more fun way to play it. Instead, we spent a whole season waiting and waiting to finally actually see vampire Guillermo, and we... never fully got that at all. He did look good with those fangs, though.
Pros:
The Morrigan Manor stuff was so charming and fresh and different. I truly had no idea where this episode was going to go, from the invitation, to the amazing fencing choreography with Lazlo and his large group of combatants... I even thought the Guide's role in the story added something fun.
All season I've been complaining that they haven't done enough with the whole vibe of her being an outsider, but in this episode, when she finally takes matters into her own hands, I did feel the weight of her relative insignificance all season, finally coming to bear. I realized pretty soon she had to be behind all the disappearances, but it was still fun to see it play out. And I like how she acts as a contrast to Guillermo, who now feels included in the group in various ways. One good moment is at the beginning, when the recording says "six of you" and they're confused about the number six, because they were forgetting to count the Guide. Which means they think of their family as being five people, and that includes Guillermo. So sweet!