I've now watched all of what they've released of it so far. Barring something really dumb in the last two episodes they're holding until July I like it a lot better than season 3.
It's got rather slow pacing, and key characters have been sidelined for most of the season. They now seem to be allowed to make episodes as long as they feel like and episode 7 is like an hour and 40 minutes long, and I'm not complaining about that (I've liked every episode), but it defitely is taking it's time. It feels like it's all building up for a big season 5 finale, so ultimately it feels like a season we can't really judge until we've seen the conclusion.
What I dislike about season 3 is that, whereas in the prior seasons the non-fantastical elements seemed grounded in (a heightened version of) 80s reality, in season 3 the Russian base, and even the mall seemed to be grounded only in 80s movie reality. Yeah, that's totally what malls are like in 80s movies, but if mall culture like that actually existed it wasn't in small town Indiana. Add in some obnoxious character arcs and it is a clear low point for the series. Other characters get great development in that season so I won't write it off completely, but I like all the other seasons better.
Season 4 doesn't have anything that really bothers me other than finding some of the characters frustratingly underutilized. But I think this has more to do with having lots of characters at this point, and wanting to get some of them out of Hawkins.
