As implied by the ending of the first season, FnK is a direct continuation of the story. Several new characters are introduced almost immediately, and, while I don't have anything against them, I'd like to point out that they (most notably Agnes) take up quite an amount of screen time with their own subplots, leaving less for the overall story. Thankfully, they aren't dragged out for too long. Particularly refreshing is the noticeable advance in Saito and Louise's relationship, during which several important questions are raised and decisions are made.
The animation is done on a fairly high level for the time, although it's not anything outstanding: characters still talk out one side of their face and all that, many scenes lack smoothness—just like in the first season, all things considered. Some scenes, particularly those of burning villages, are pretty nicely done. (I swear I'm not a sociopath!) The sound work borrows most themes from the first season. They're fine for what they are but still come off a little generic. New opening and ending are somewhat enjoyable, definitely more so than those of the first season IMO.
As for the characters, the previously known Academy residents (Kirche, Tabitha, Guiche, etc.) have much less screen time. Not sure if I like that; personally, I'd prefer to see them some more. New characters are passable, if a bit queer-looking. Siesta is still there, being apparently dumber than previously. Yes, everything has to be sacrificed for the sake of fan service. (sigh) On that note, what is particularly annoying about FnK is that fan service has increased in quantity, but definitely not in quality. Saito's obsession with boobs might've been funny at first, but the obviously contrived situations become old very quickly. You might not even notice it at first, but by the last episode it will come screaming in your face. Then again, the finale itself is too silly, anyway.
All in all, with FnK Zero no Tsukaima keeps being a good addition to your collection as long as you enjoy fantasy harem comedies with a questionably high amount of hit-and-miss fan service. Many will laugh, some might even tear up; overall I think the second season is almost as enjoyable as the first, barring the certain cheesiness and an overall drop in the quality of the comedy. However, it might leave something to be desired when it comes to the story progression, so I sincerely hope they won't drag it out for too long. Any further decrease in pace coupled with an increase in fan service could easily ruin the show. (Editing this paragraph from the future: It did ruin the show.)
