Review aggregator Rotten Tomatoes currently has the film at 94%. With 33 fresh reviews and 2 rotten. Average rating of 8.3/10
Incredibles 2 has an extremely promising score of 85 on Metacritic.
Some Youtube Reviews:
Embargo just lifted so expect some more to start coming out, and of course Pixar Post has their own review here in the website.
So far, it seems that people are mostly positive on this film, it just depends on how positive. I'm seeing a lot of "This lives up to the original" and little of "This is a B-Sequel from Pixar". Let's see how it continues doing. Keep an eye out for Rotten Tomatoes score changes.