Falls just short of the MCU gold-standard, Winter Soldier, but a great movie. Must-see.

Rating: 10/10 (27 April 2018)

I've heard and read comments that the humor in the movie wasn't entirely appropriate given the dark nature of the premise. This is Marvel. Marmite - you love the humor or you don't. I do.
I'd rate this a solid 9 out of 10. It was definitely the "Empire Strikes Back" of the MCU - or at least that's how it felt. The Russos did a great job of bringing the tone and style of each of the franchises together.
Standouts were Thanos and Gamora. We know Spidey, Black Panther will be back as their solo sequels have been announced. Gamora's fate only realy pays off is if she stays 'dead'. I worry that she won't. I love Zoe Saldana and Gamora, but narratively her loss would feel empty if she was resurrected or brought back via time-travel or something like that. Losing Hemidall was emotional as well - but Idris Elba is too big for a cameo part in the MCU. Loki needs to stay dead as well. Tom Hiddleston, for me, is still the standout villain in the MCU, but his death is a catalyst for Thor's story in the movie. With so many characters 'dissolving', it did feel like it devalued some of the other deaths - Gamora, Loki, Heimdall. This is the reason i can't give it a 10 out of 10.
With so many characters to give dialogue and screen time to, fans of specific characters will feel disappointed their favorite didn't get more - especially Black Widow. But great fight between her, Okoye and Proxima Midnight. Thor was an unexpected highlight - the emotional narrative - and great to see the introduction of Stormbreaker.
Overall, a fitting way to bring together 10 years of the universe. Was even good to see General Ross and Red Skull.
One final thought - great post-credits scene and would love to see the post-credits scene in Captain Marvel, where Brie Larson's Cap receives the encoded distress message from Fury, and she unloads a whole bunch of whoop-ass on Thanos.