Holy fankwank! Not a bad episode by any means, but still the weakest episode of the season to date.
There were still a lot of good character moments in this episode. The scene between Jack and Sydney legit got me to tear up a bit (amazing, given I don't really give a crap about Voyager much). I liked all of the Jack/Picard scenes, thought LaForge's reintroduction was done well (with a complete character arc), and I liked seeing basically the whole gang together and interacting again.
But much like the season premier, this episode relies far too heavily on nostalgia and memberberries. Things like the return of Moriarty had absolutely no reason to happen other than to just have the audience go "I remember that!" Tons of group dialogue scenes which basically existed to make the plot move forward as well. It absolutely gave the episode the most TNG vibe to date, but it meant it just didn't feel as consistent as the last several episodes. Plus I kept being reminded of how heavily I was being pandered to, which took me out of the story.
I really, really don't like the resurrection of Data (with multiple personality disorder, so Spiner can keep mugging for the camera!). I know Matalas has different ideas than Chabon regarding the series, and Trek has undone many deaths before (see Spock, Picard, or the first time Data died) but this basically entirely undoes the one good thing about the finale of Season 1: Data's decision to die, because he felt like mortality was the ultimate expression of his desire to me human. The choice Data made in that episode is now useless; robbed of any emotional context.
Not sure what's going on with Vadic at the end? Seems to imply there's different factions within the Changelings, and she's actually a more sympathetic one. Maybe she's playing a long con - trying to trick her masters into thinking she's on their side, but she needs Jack for something else.
Regardless, it's still enjoyable, and the plot was moved forward. Not every episode in a season can be equally incredible.
Edit: Oh, and I really hope Jack and Sydney get together by the end of the season, with all that chemistry.