For me the third season of Zero no Tsukaima wasn't anything special.
I loved both season 1 and 2, but the season was disappointing.
The amount of girls that has joined Saito's harem has gotten out of controll. And it is frustrating watching.
Something that disappointed me most was that J.C. Staff seemed to be focusing on fan-service and the story didn't progress as much as it should done. And the story was very repetetiv.
And the end of this season was far as saticfying as the two first season. If you love fan-service and some lesbian action you should enjoy this, but if you are like me that only gets embarrassed watching fan-service then this should be a problem.