Just finished S5 and quite enjoyed it. It was a bit drawn out, but as the culmination of the series, I think it should be allowed. Took a minute to read up on the Internet's opinions on why I should hate it and think those opinions are largely bunk given by people who don't really pay attention or can't feel emotions. I strictly avoid anything that smells like a spoiler, though, so that may have something to do with it - no "hyped" trailers to mislead or disappoint, or knowledge of plays with special lore. Honestly, it feels like people go out of their way to ruin things for themselves. I saw people stressing about how the actors said things in interviews "meaning" certain things for the show. Madness.
Anyway, Holly was a great inclusion to the season, and additional evidence that the Wheeler women kick serious ass. Max/Lucas were both standouts, and Dustin. If I'm being honest, I lost interest in El's whole schtick a while ago, so that didn't really hit for me, but I did like the relationship stuff with Hop. My only big hangup (for the whole series really) is the discrepancies with the ages of the actors. I get the Duffers had a specific vision, but a few time jumps would've done wonders. Still, I thought the epilogue was very sweet. Teared up myself at the final D&D session.
Overall, well done final season even if it wasn't perfect, and honestly it's just nice to see a series have a clean, definitive finale. So many just go on and on until they crumble into insignificance.