First the most important thing, and the only thing that I don't actually like about it, is that you have to watch the TV series and it would be highly recommended to watch Tsuioku Hen as well, the reason is that it is all based on what is there, without that it is an already started story that you won't pour yourself since the lack of introduction, this it is technically the conclusion, and a master piece of conclusion in my opinion.
[Spoiler: Rant about Authour Opionion]
Let's go on, If someone doesn't like this OVA, it is fine, I really see why, but when people throws the lame excuse by using a phrase that the Author of the Manga said "Kenshin went through so much crap and deserved a happy ending" which he actually said, I'm glad to show them my middle finger, since them can't even give their own arguments to why it sucks, but not only that, the thing is that when I read that sentence I was really curious to think why he though that, I was blissed with the OVA that just got me intrigued. I laugh to them even more, people are using a sentence out of context to trash this OVA. Here is what I found on wikipedia: "Although Samurai X: Reflection was not written by Watsuki, he stated that he "checked in on the script." Watsuki mentioned not having input in it, and let the director "run wild with it." In response to Kenshin's death in comparison to the happy ending in the manga version, he felt that his own work eventually would have reached Kenshin's death had he continued writing. He had not wished to pursue that line because "Kenshin went through so much crap and deserved a happy ending." He felt that neither version was better than the other because "it's a personal taste thing." Here is the actual interview http://www.mania.com/anime-expo-friday-report_article_86123.html where he actually flatters the OVA as interesting. So to give a director a second chance to go wild on a script on one of his beloved stories is because there is actually respect from him to the director, as he as well accept the cruel fact of what could have been on the manga and was actually in this version, were it is really a matter of taste which one you prefer.
The thing is that most of people think of this as an full adaptation, and it's clearly an INTERPRETATION just by not listening Kenshin saying "oro" and the bittersweet realistic athmosphere, adding that this is not written by the original author. The key is that if he actually respected the essence of the story, and I think it actually was marvelous on it but on the almost literaly opposite point of view. While the TV format was more focus cheerful, childish, good spirit, it also had serious and mature matters as well for sad strong emotions. Here you got that on reverse, grimace, mature atmosphere and harsh reality, but it also had moments of beautiful warm hearted moments.
It use a lot of flashbacks, you actually see a summary of the whole TV show adding the Enishi arc, which does feel strange since it was a kind of harsh change on the pacing, but I don't blame this OVA I blame the stupid last 33 episodes of the show for exploring the mysteries of religious treasure hunting fen shui, instead of actually going on with the plot since I read that Enisihi arc is pretty kick ass and it seems so. So this was necessary for those who didn't knew about this arc and because it actually has to do a lot with Tomoe which is heck of important as important for Kaoru, but they deal with this summarized arc just as they should.
The main protagonist here isn't Kenshin, it is Kaoru, and I actually was afraid of this when read the premise, just happen that It is just really hard for me to take Kaoru seriously on the Show, she is just so blind in love for Kenshin that I just can't end of understand in detail why? is just so childish, and don't take me wrong, I actually think she was a good character in there, it actually had good development. What I got here? I couldn't be more satisfied, it is almost as Ruruouni Kaoru since we see all from her perspective and it let me clear what was going on with her and his love for Kenshin on a full panorama and done just right. All the other cast also receive their importance and dedication, but compared to the shounen style of the TV it is actually pretty subtle due the realism, so if you like explicit and exaggerated emotions you might not get what you ask for, but they stay faithful to the spirit of the characters, except for one and clearly the biggest complain.
Kenshin is not the same, is the same from Tsuiokuhen, but not from the original story one. What we see here it actually contradicts the point of view of the original story, or what I understood, since Kenshin is very cheerful despite of his grimace and actually could fight with the guilt of the past. Here the story starts telling you that it was all a LIE! but remember, this is an INTERPRETATION a SPIN OFF, a PARALELL UNIVERSE, I don't know how would call it but is not the same line, that you can guess just by looking without much depth. And yeah, I know, it sucks at first sight, that's why not giving the whole credit as something perfect, since the contrast is just too big, but I don't blame whether if I like the other the best or not, instead I go for how they play with what they choose, and they did a perfectly legit Kenshin, having Tsuiokuhen as a base, and a full show were you have to unfortunately figure out how it went so he took this path, on the other hand they give a lot of backdrop in here so it's very easy to figure out how it all went, and I have to say that I really like this Kenshin, although I still prefer the "oro" one because he is the awesome classic one.
I just love everything, the presentation was outstanding, moving through flashbacks to flashback to the present to flashback in a very dynamic and fluid way that doesn't really gives you the feeling that you are in the past but actually living the present of the memories of the characters and the way they act so real and human with a lot of emotions everywhere with a very good direction, I was immerse from the beginning to the end so easily with the help of the music and animation, for me this was just a fantastic ride even better than Tsuiokuhen, and a Master Piece
Animation (Great) Sound (Superb)
As for the animation, the little of action is done very very neat, as well for the atmosphere, the character design feels a little bit odd but when getting used to, they are great, my only complain tend to be some still expressions they make from time to time. But outside of that it is a fine piece of art, including the high musical standards of the Kenskin franchise.