There are two things I dislike. First, the slo-o-o-o-w tempos. Some parts--some entire songs--drag on like dirges. No wonder this recording went to two discs.
I also don't care for Daniel Evans as Act One George. He has a Scottish accent which get muddied up throughout (especially during the part with the two dogs.) He has a beautiful voice and I think he's fine as Act Two George, but I don't think he carries off Seurat at all. (Is Act One George ever referred to as Seurat? Hmmmm...)
Otherwise, I love Jenna Russell as Dot/Marie. Not as good of a singer as BP, but she acts the roles much better.
I also like the new orchestrations. In fact, I like how this entire recording sounds. I don't know what the technical term is, but it's the "warmest" cast recording I've heard in years. There's a robust, full-bodied sound overall.
And it's a treat to have the entire score included, though I wish not as much of the spoken dialogue was present (a wish I have for all cast recordings in general.)
Actually, the tempos don't bother me too much. To me, there is so much variation in theater music and subsequent recordings that I've gotten used to that kind of change.
Georges in the first act didn't seem to be as obsessive as I though he should sound (well, from what I could hear from the recording). Of course, I could just be too used to Mandy's version.

I enjoyed Dot/Marie, also.
I like the fact that the orchestrations are different...at all. I have a studio cast recording of
A Little Night Music with Sian Phillips as Desiree (who went on to play Madame Armfelt with Judi Dench as Desiree) that has a string quintet (I think) as the orchestra and it's beautiful.
I also love the fact that so much of the music is included, but I like all the dialogue. I like getting a sense of
the show, not just the songs.