Last year, Eureka felt like a guilty pleasure. It was pretty goofy and cheery and pleasant. On the other hand it had a nice level of arc-ness, and never felt like it was Abrams-ing with "the artifact"; it seemed likely we would make progress on that at a regular rate. And some episodes played pleasingly with science and sci-fi tropes; "Before I Forget" was the standout for me, seeming very clever in how it balanced what the audience knew and what the characters knew.
While I'm not exactly thrilled with the direction they're going with the artifact storyline (one word: Dawn), this episode was mostly awesome and mostly awesome in what it sets up for the future. Watching Jack trying to deal with his memories of "Allie" is great fun (this episode was mostly awesome), and not having to watch this for the rest of the season is the right call (mostly awesome in what it sets up for the future). Henry's line "Jack, you're my closest friend, and intellectually I know that you had to prevent me from saving Kim, but emotionally I blame you for her death; I can't look at you without thinking that you're the one who did this, that you're the one who took her away from me" is just perfect for ur-scientist/rationalist Henry (this episode was mostly awesome)--although on rewatching to get the quote I'm not quite convinced with Joe Morton's performance as he scales up the intensity for the second half and then backs down at the end, but on first watch it was great). And having Henry not lose his memories, and having this chip on his shoulder against Jack that he knows rationally he shouldn't have, and his likely scheming to find a way to bring Kim back, should make for interesting interactions and an interesting arc for the rest of this season (mostly awesome in what it sets up for the future), as well as giving Joe Morton something to sink his teeth into, instead of being mister answer man. (Seriously, I'm fairly certain he's the best actor on the show, and I was really worried last season when his character was intending to leave. Non-departed Henry is awesome; non-departed Henry with actual stuff to do should be great. (Of course, even with nothing to do, Joe Morton is awesome; watch the parodical[*] power-station tunnel one-take walk-and-talk in Dr. Nobel, when Henry doesn't speak until they end; Joe Morton just plays Henry nose to the grindstone, barely paying attention, in a totally convincingly scientist-y way.) Also, he does a marvelous job of interacting with CGI holograms and user interfaces that aren't there when he's acting; there's an example or two in the Dr. Nobel as well.)
[*] I assume.
So, yeah. Cool. Hope it stays on the darker side of things while figuring out how to stay true to the premise.