I binge-watched the entire thing last night.
It's really, really good. It's so well done it basically feels just like an extended classic 80's Amblin/Spielberg meets John Carpenter and Stephen King movie rather than a TV show, albeit one of those ones you 'just never saw when you were young, ans so only just got round to watching now', and I love it for that. The 80's atmosphere is so well done, it conjured up so many great memories of the kinds of movies I used to watch back then.
I too was wondering how well they would end everything, but it turned out to be very satisfying, while still leaving one or two intriguing things dangling for a (hopeful) second season. The trailers looked like exactly the sort of thing I would enjoy before it came out, then once it did I heard nothing but good things, and yep, there's a reason for that. Really great stuff.
The only downside now is waiting a minimum of another year to see what happens next (if Netflix gives it a renewal of course, which at this point they'd be crazy not to)!