Wow, I finally caught up with Zero no Tsukaima (Final) and got a perfect timing with the latest episode which is Episode #6.
So, Saito and Louise are still "developing" their relationship between each other like it has always been since the previous seasons. But, we actually get another nice sweet fan service of the female candidates once again which I believe which is the first one of this season. (Technically, every episode has some sort of fan service.) Ahem, since this is just plain "fan service", I really can't say anything about much but we do get to see how the each of the female candidates feel about Saito (which I think is dayshavoo) and a cliff hanger near the end that will lead to another episode. If you still enjoy fan service from Zero no Tsukaima, this episode is somewhat a must watch. If you don't enjoy pure fan service, unfortunately for you, this is still a "must watch' because it's part of the main story arc. Zero no Tsukaima is after all, one of those comedy echii fantasy anime. Overall, I decently enjoyed this episode and it's quite romantic (which is still dayshavoo in some way).
Conclusion: A sweet romantic decent fan service.