Someone got to play the demo in Japan (which is the final build, just not all characters/stages available), and here is the full list of impressions
Some of this stuff is way over my head having not really played SSB competitively, but so far the majority of the changes seem to be for the better!
For the record I'm super happy to hear Robin feels great, sounds like my kinda character. Shulk even more so. I really want to try out everyone though. Man I cannot wait for this game...!