My overall thoughts on fate/stay night UBW is that it had something promising after season one but ultimately was lacking and was missing something. I think that the animation alone is a reason to watch the fate series despite it's flaws.

Plot [7/10]: I'm assuming you have seen UBW season 1. There are a number of plot twists within season two but I am not a fan of them. Frankly put, it is revealed that information that was given initially to Shirou, Rin, and the viewers are essentially just lies and the true nature of the Holy Grail War is something different altogether. Compared to the VN, UBW is considerably shorter and things have to get cut inevitably. Sometimes things aren't well explained and things simply happen. My issue with the plot twists is that they simply aren't significant to have any shock value. Now I'm not saying that Shock value is anything necessary, but regardless of the true nature of the holy grail war, they still have to fight the same people, so what's the point. Moving on, the story has an overabundance of plot armor. This is a big issue for me, Never did I feel that Shirou was going to lose and this is amplified by the attitude of the characters. Both Rin and Shirou by nature tend to be very stubborn and steadfast and they never really lost hope, even when the odds were literally zero to none. Obviously, the MC is going to win out in the end but in UBW, everything just runs too smoothly and happily-ever-afterly. Shirou's main ideal of being a champion of justice is rarely challenged outside of long rants from the antagonist. I feel that a major setback like Shirou failing to save somebody would be a welcome plot point to develop Shirou's standing desire to attempt to save everybody even though it's impossible, yada yada yada

Characters [7/10]: I won't say that the characters are unlikeable by any means, because they totally aren't. What I am saying is that the story is so plot-focused that there is rarely any opportunity for character development. The characters are pretty one-dimensional so it was hard for me to discern whether I liked them or not. I will say that a majority of time is spent on Archer in UBW season two. Regarding this, I will say that he is the saving grace of season two because the dialogue regarding Shirou's ideals of being a "champion of justice" were thought provoking and intriguing, even if they were heavily drawn out. Regarding Rin, I like Tsunderes (Asuka, Nino, Kurisu) but she gets flustered toooo easily. She's cute but overdone for me.

Voice Acting [6/10]: I want to add this separately from soundtrack. I feel like some of the characters did not fit their voice actor. For example, I don't think Sasuke Uchiha's voice actor fit the mold for Shirou's character at all by any means. I thought the Voice Acting quality wasn't bad, and it didn't hinder the show, but I 100% think that they were dull, stale, and lifeless at times and the show could have been better with a better performance in this department.

Soundtrack [8.5/10]: The orchestral music that was used in fight scenes is epic and awe-inspiring just like in season one. I don't think there are any groundbreaking sounds but the timing in which they used their sounds was excellent.

Animation/Art [10/10]: It really does not get better than this. For a 2D production, the fluidity of the animation not only holds up in comparison to, but exceeds many anime, nearly a decade later in 2023 compared to 2015. It's something that you have to see for yourself, mere words on a screen does not do it justice.

In conclusion, I think that many, or even most people will definitely enjoy Fate/stay night UBW. I personally enjoyed and appreciated it but was ultimately disappointed given the heaps of praise it received. I think the animation and visuals did a lot of heavy lifting as someone who cares deeply about the plot and characters. The final verdict is that you will probably enjoy UBW more than I did but it really isn't anything groundbreaking plot/character wise, you can find better anime there. However, when it comes to animation, ufotable x type moon are second to none. Final Score: 70/100