Zero no Tsukaima F is the final season of the series and it features a young boy Saito getting abused by his master Louise. Stuff happens, Saito is extremely indecisive about his relationship with Louise, stuff gets fixed. Nothing new is really found in this season and I won't go too much into detail about the summary because hey, you should have seen the previous three seasons before you watch the 4th one, no?
So about the story.. heh. If you have seen the previous seasons, you'll have a pretty good idea what happens. Some stuff happens, maybe some random fanservice here and there, filler episodes randomly thrown in out of nowhere, a problem occurs and is solved with usually an unrealistic solution that probably has some plot holes. And by plot holes, I don't mean "look very deep into the anime" ones, I mean "wtf how did they just do that it didn't make any sense at all" kind of plot holes. It takes the fantasy genre to a whole new level and again, its not in a good way (example: Saito stealing a fighter jet from a military base). Some of it can be attributed to the fact that the majority of the season was rushed but all in all, they really did not need some of the fillers; it was just a waste of time. If you're one of those people that like to have an intricate plot with plenty of BAM moments, this is not the anime for you. The plot is lacklustre and very predictable. Because this is the last season, the end has to be taken into the score as well. Personal I thought the ending was very predictable but it fits the anime. Having said that though, ZnT is NOT about the story. If you have been watching this for the story, then I got news for you, choose something else to watch. The story here is just there to have at least some "meaning" between each episode, nothing special.
Al-right, the characters. The characters are again, nothing special. An abusive tsundere, some boobs, some more boobs, and a loli. This anime throughout the seasons has shown no character development, Louise and Saito were supposedly married at the end of season two but Saito is still an indecisive guy and Louise still blows him up. Usually this would lower the score as dynamic characters are always good but the thing is, it's what the anime is known for. This is why most people have continued to watch though the seasons. Sure, Saito will piss you off every time he ogles some girls breast because he completely lacks self-control or some other stuff that ticks you off. The non-changing character foils that have been constant throughout all four seasons is the selling point of this anime. You don't watch this to see some well thought out strategy like Death Note or the plain awesomeness of Steins;Gate, you watch this too see Saito getting blown up by explosions and the tsundere Louise being her usual self and the relationship between them.
The sound doesn't really do much considering most of the BGM is just reused from the previous seasons. In some cases, it certainly does help set the mood and I loved how they reused one of the openings during one of the final episodes. The energetic OP also adds towards the enjoyment of the anime; it fits the mood. Though the EP isn't bad, the usage of it is certainly questionable in some cases. Something some by Rie Kugimiya doesn't really fit certain situations if you know what I mean.
The art wasn't really exceptional and doesn't take away from the anime itself. Not much to comment on this as it doesn't feature any special art style. The battle scenes were too short in my opinion.
I'm a Louise fan so this is probably biased but I really enjoyed the series overall. If I was to use by biased score, this would be a 10/10 just because I'm a huge Louise fan. That's kind of the thing with this anime, either you'll hate the characters (I don't think many people expected much out of the story anyways) or come to love em. The story was really annoying at certain points because of the number of episodes that were just pointless. They could have easily just spent a couple of minutes or not even included certain parts (really didn't need a episode dedicated towards the crowning of a queen) of the anime. The ending however, was probably the saving grace for this anime. I personally value a conclusive ending opposed to some random harem ending. Overall, I think that this season manages to set up the end of the series only leaving some minor plot holes. Watch this with a grain of salt in mind.