I don't know if I ever experienced and had a development process, like the one I had with Gosick. With the last third of episodes, my impression and view on this anime changed completely. This already implicates that I absolutely disliked the first two thirds of the total episodes.
First we start with a very interesting setting. As a person that takes a considerable interest in history and different ages, I was curious and pleased about the period in which this series is set. But now I have to talk about the aspects I didn't liked, which counts for the most part after the start of the anime (until episode 16 or so), and that are mainly the characters and partly the story.
Until the mentioned episode and point in the story, it were the characters that got on my nerves highly and would have brought me to interrupt my watching of the show, if my watching routine wouldn't exist. With Victorique we have the generic tsundere, prideful, arrogant, violent if she's embarrassed and antisocial to her environment. This was already tough for me, but with her counterpart it got even worse, Kujo Kazuya, a character that has no self-dignity or self-concious whatsoever, can be bossed around all the time, has no physical presence which I want to mention because he can be seen falling and pushed literally in every episode, and that can hardly stand up for himself, but at the same time wants to do this for others, a contradicition that is shown more than one time in the anime. His greatest strengths are probably empathy and careness. What bothered me the most for the large part of the anime, was their unequal relationship, how he always let himself put down by her, and how the anime bluntly tells that this was slave and master relationship (at first), even said so by Victorique and that he only serves to reduce her boredom. In regard of the story I can say, that I just didn't like most of the short story-arcs until episode 16.
In another paragraph, I would like to deal with Sherlock Holmes, who can be used in this context and was mentioned in one or the other review. I also saw the parallels and references to Sherlock Holmes, basic of the plot and in the representation, roles and habits of our characters. But as a huge Sherlock Holmes enjoyer and fan I want to answer back in one point, if Sherlock Holmes who's by the way, way more charismatic and likeable than Victorique (during the first 16 episodes), would have had a useless partner with less to zero personality by his side like Kujo Kazuya, I would never have become a Sherlock Holmes fan in the first place. But to be fair, I liked the other similarities, between these fictional works in the usual way.
Spoiler, click to viewclick to hideTo my personal happiness, with the progression of the anime, the characters and their relationship experience a development as well. Victorique becomes more and more likeable, she discovers things that are more precious to her than her pride, and the viewer develops a stronger understanding for her with successively more parts of her backstory are leaked. The relationship of the two becomes more natural and healthy. They verbalize and speak out their appreciation, acknowledgement, and sympathy for each other and even the so prideful Victorique can compliment others. Sadly the character of Kujo Kazuya doesn't experience any kind of development. His weaknesses and deficits stay the same and his role in the final arc corroborate this impression. Rarely I didn't care for and didn't like a main male character, like Kazuma Kujo in Gosick.
But not just the characters, the story also shows an improvement during the last episodes. The arcs are intriguing and thrilling, the drama becomes more intense, and the story with its different characters is culminating in a brilliant and spectacular end, which I would classify as one of the best endings in comparison to all of the anime I've seen so far. The central theme becomes clear and all the plot lines that were tackled in the anime are brought together.
The music was also very good with a pleasant opening and to great endings :) The musical accompaniment in the anime was also good and fitting but to nothing stood out for my personal taste.
I nearly forgot the side characters. The anime covers a large range of them, from very good like Brian Roscoe, Cordelia Gallo or Grevil, to uninteresting and boring like Avril Bradley and Cecile.
I can articulate that near to the end, it became a really enjoyable and entertaining anime to me, with reductions because of the poor beginning and considering the hard times I had until the middle of the anime with the things I didn't like, I sadly can't give it more than seven points out of ten (Which is a poor and low rating for my standarts). For fans of the mystery and romance genre it could be worth it, but in the end I wouldn't recommend it.