Cpt. Janeway, Mrs. Frederick, and even Spike from Buffy were all there. I loved it, but will keep my assessment spoiler-free for now.
Long story short, everybody was in top form. It was emotional, tense, funny, and fast-paced: all the things that make W13 great. And it set up the new baddie(s) for the rest of the season, which was a nice unexpected touch.
James Marsters was, per usual, brilliant, and hearing him with a British accent (albeit a stuffy one this time around), was a hoot.
If I go on anymore we will get into spoiler territory, so I'll leave it as is. Just go and WATCH it!