Now... my feeling of the anime were, in the end positive. Detailed breakdown is below.
Impression/details in no particular order.
The overall story is fairly weak for a monogatari series, and feels very drawn out. The first story ark in monogatari has a very strange choice of a subject that is very unusual for monogatari series, and felt out of place. The character of the first arc (around which the mystery was centered) felt like a character borrowed from some different series.
There are many situations where prolonged monologues and dialogues feel a bit too drawn out, even for monogatari.
I'm also not exactly sure why this anime is so obsessed with school desks. In almost every abstract background this anime uses, you'll see a large number number of school desks moving around, being repositioned, displayed from different angles and so on. Monogatari uses repeated/patterned art/episodes a lot, but this is pretty much the first monogatari season where I started noticing school desk reuse in the scene.
Overall, my impression of owarimonogatari would've been negative, BUT.
First, the series had opening song ("decent black") in first episodes which I greatly enjoyed.
The second positive is ... each arc of owarimonogatari has a character araragi interacts with a lot, and in all cases that character is fairly well written and interesting to watch. Interactions with a "focus character" bring life to all arcs of this anime.
Speaking of characters, Oshino Ougi is a very powerful presence in scenes where she appears, and aside from her there is an infrequent but highly entertaining scenes with witty/entertaining comedic dialogue, which is not really related to the story.
So the bottom line is...
Aside from final episode that has a genuinely interesting moment, the "central story" is not that interesting, but the show is worth watching because of interesting opening song, powerful "side" characters and humor in non-story related dialogue. Oshino Ougi alone is a good reason to check the serious out. Just don't get your hopes too high about the central story of this season: while there are great characters and scenes where this anime shines, there are plenty of disappointing moments. The reason why I've rated the anime high despite this issue is because good moments overshadowed bad ones. So, basically, there are a lot of moment where the anime doesn't feel very special, but among those there are less frequent moments where it becomes really great.
