Saying it's "much better" would be fighting words with a lot of aficionados.
That said, it's very well done. I enjoyed it. Considering Sondheim's and Bernstein's works, you'd be hard pressed to change much. The updated feel, while still being exactly the same story (although not always in the same order), makes it seem much more accessible to a modern audience.
They didn't smooth out much, but "I Feel Pretty" was changed to "I feel pretty, and witty, and 'strong'" or something like that. I guess they didn't want it banned in Florida.