Wolf's Rain is a very mature seinen-Esque anime.. with a dystopian setting, subtle but ever-looming philosophical themes, a semi-melancholic/gloomy vibe and an extremely subjective ending. The overall satisfaction you get from Wolf's rain and how much justice it gives to its premise entirely depends on you. For Starters, the anime is a mixed bag when it comes to its characters, while Tsume, Toboe and the remaining Humans seem to be fairly well developed and are portrayed to be quite believable as characters (What I mean is the characters don't adhere to the stereotypical archetypes like Tsundere or Yandere and gradually change as the show progresses) while some characters like Cheza, Kiba and Hige can get boring and repetitive until the few final episodes come out of nowhere and throw some plot twists/revelations in our faces, which to me seem really quick. In fact, I feel as though, the final jaguara arc felt a little out of place and they could've made it a bit less anti-climatic and still could've given away the philosophical lesson/moral they wanted to give. It's just something I feel, considering that the buildup towards the final episodes was really happy in tone and quite interesting to watch and the end kind of washed it all away. Because it seemed to happen in a flash. Some anime can work along pretty well with such endings, in the case of wolf's rain, they could've made it slower and less abrupt, to give its past few episodes and deep themes more justice.
I did watch the OVA's but they were heavily spoiled to me, so the enjoyment factor kind of lowered down, but I still think had I not been spoiled, I would've still felt that the ending could've taken a much climatic turn. To sum it up the first 18 episodes (not counting the recaps) were good, the last 4 not that much, and the OVA's got affected by it.
I expected a bit more of an ergo proxy type ending as I've found a lot of similarities in both of the shows.
As for the writing, the condition of wolves, worldbuilding and tieing of plot twists were done pretty well, and the subtle symbolism and the philosophical themes related to paradise, meaning and drive in life were explored pretty beautifully as well.
The World was likeable yet depressing.
The Art and Animation was top notch for 2003 and at times the scenery felt beautiful to watch and all the design work was done really well.

Final Verdict- Watch this anime for its meaningful themes, great worldbuilding, character exploration and if possible ignore its anti-climatic ending
This is a mature anime, but anyone can watch this because this isn't obscene or vulgar in nature

on the note the first 18 episodes- 90
final episodes- 60

overall score- 83