Pros:
Worth the ten years invested in the MCU
THANOS!!!
Thanos is a complex and Powerful MCU Villain (the Best yet in my opinion)
The Black Order are great henchmen
Movie spans multiple locations with impressive scale and visuals
Plot moves along at a brisk pace
Abundance of team-ups and great action sequences
Does not suffer from too many characters.
Multiple Easter Eggs and call backs to earlier films in the MCU
There is a clear sense of danger and possible doom for the heroes
Awesome Humor
Darker tone than most of the other MCU films
Amazing soundtrack and score
Great CGI
Did not spoil plot in trailers
Lived up to the hype!
Leaves the viewer wanting MORE!
Cons:
We have to wait a year to continue...
Sometimes it felt like Thanos was "nerfed" a bit or was holding back.
Wish the film was like 30 mins longer
This was more a coming out party for Thanos and less an actual “Avenger Film”