While I enjoyed Guardians of the Galaxy 2 and wouldn't call it a bad movie, I have a pretty negative opinion of it, here it is:

Its choice to rely a lot on popular culture to build its identity is not very well executed. The reason I love other MCU movies so much is that they look like they try to build contemporary pop culture, and that feeling, for me, was completely absent from GotG 2.

As a result, I think it will age pretty poorly compared to the rest of the MCU, but only time will tell