I just saw it and gosh. I don't know what to say. I liked it more than The Force Awakens but damn... They shit the bed with this one. I can't really say much about what was wrong without spoiling it, but it single handedly betrays a lot of what Star Wars is all about. Furthermore it's not much of a sequel to TFA or even really fits with the rest of the saga. People are right about Snoke being underdeveloped. In fact his character holds no meaning to this trilogy at all. He's more or less a plot device to drive Kylo Ren. Speaking of plot... The Last Jedi has a plot but offers little in terms of story and narrative. It's very inconsistent and drops a lot of plot points. For example the Knights of Ren have been dropped entirely from the series.
Something I find interesting is that there was a plot script that was released last year for the film. A number of things were correct. The title being "The Last Jedi", a new character named "Captain Canady", a Casino planet, and major epic space battles along with Poe being a star of them. That being said the plot was changed drastically for being too ambitious, too big in terms of scope and vision, and potentially too much risk in terms of plot twists. It's a lot more "Rain Johnson" than what we got. The script is much more consistent with TFA, includes the Knights of Ren which played a major role, and Snoke was a huge character and consistent with the books. The narrative over all was amazing and one of the best in the series. I really wished I knew what went wrong with this films production. It's clear from watching it that Disney really backed down on their grand vision for this trilogy. I still got a copy of the script if anyone really wants it.
If anyone has any questions, I'll answer them with spoiler tags.