I like it, with a few reservations, but not many.
I'm glad so many sources are pulled in to it, so now at my table - where we use PHB+1 book, like Adventurer's League - most of us now use it and it covers all the things we need.
I think the fact that we've seen everything in UA is the best part. How they did it, what they put in, what they kept out, etc. shows the process from beginning to end, and it's transparent and sensible. It's really well balanced for the most part - I know I've been looking over most of the classes and as much as I want to try them, I see what I'm giving up to get them, and it feels like a really tough decision. The only ones that stand out as definite 'must use' are the ones specifically put in as alternatives to known weak classes in the PHB.
I'm really happy with all the charts. This fills in big gaps that had a bunch of us at our table running to 3rd party websites constantly. They're well-done, and really buff out our hex crawl / West Marches style game.
I also like the extended character creation. These have been things that have been lacking or iffy in earlier editions to my taste, and these are good for what they give to new players - a framework for how to think about the flavor behind a character, and inspiration that will bolster their own creativity.