Completed the main quest and the Rainbow Rocket episode.
I said this about the original SM and I'll say it now, it's nice to finally have some challenge in Pokemon for once. The trials, especially the electric one, required patience and strategy. You can't just over level your starter and clear the game. It is pretty similar to SM, but more streamlined and with better QoL. From the Aether Foundation onward the story takes new twists and turns, most of them appreciated, though as Gamefreak pointed out in his post, some stuff is missing, much to the detriment of the story.
The Rainbow Rocket story segment though is pure fan service. I had a lot of fun with it, even if the level jump is a bit crazy. My entire team was about Level 70 for the final battle and I walked away with only one Pokemon left standing, and he was poisoned with 2 HP remaining. It was great fun to see all the callbacks to the past.
All in all, if you liked SM, you'll like this. Whether that's worth $40 is up to you.
Now it's time to hunt UBs and Legendaries, and then transfer my living dex via Bank.