For overall rating i would give it somewhere between 8.5/10 and 9/10. (thus - voting 9)
Animation part does not need any comments - it was top grade stuff. Overkill CG marble any one ?
Snow and water was beyond excellent as well.
Now, pacing in some episodes is something i am going to complain about... and all of them are Ayu centric
The first half of the last ep felt especially "jumpy"
I also didn't like how they "wrote out" characters once their respective arcs were over. Although they tried to justify it, it still didn't sit well with me. I mean...how believable is the fact that Yuuichi never tried to visit Shiori after she ran off ? How come he never visited Sayuri and Mai in hospital, bare the first time right after they were hospitalized ?
I was not exactly pleased that they seemed to forget Mishio's existence altogether once she had served her role in Makoto's arc. Speaking about Makoto's arc... that thing should have been shorter imo, making way for more time to blow on the ending, and making it feel less rushed.
I am not sure i am too happy about the Ayu Deus-ex machine they pulled in the end, but since it fits in with the overall theme of Kanon i am not going to complain much about it. The last episode gave the feeling of an epilogue... except it wasn't one
Overall it was highly enjoyable and high quality experience. Even though i felt it was a tad lacking at several points, it is still lightyears better than a lot of anime out there.
Rewatch is in order.
EDIT: Oh, and about the remark that this Kanon is not newbie-friendly: I wholeheartedly disagree. I am a first time viewer of Kanon, and i can not, for the life of me, figure out why that would be true. I didn't feel like i was missing anything.