All things considered, I'm a little surprised that I've never gotten around to reading this. Possibly down to the age and the fact that it is from a Marvel era that I don't always get on with.
The one thing that does surprise me is how densely packed it is. Story threads related to the Kree and Skrulls tie in to the Inhumans, Captain Marvel, Ronan the Accuser ... all before the midway point. In some respects it feels more like someone has packaged these issues together under the Kree / Skrull war banner rather than that it was planned as a standalone story.
The team of Quicksilver, Scarlet Witch and Vision is sparse but supported by Ant Man / YellowJacket, Wasp and Goliath before shifting to the classic Thor, Cap, Iron Man. Then you throw in cameos from Carol Danvers and the FF. All adding to the volume!
The artwork is definitely of its age, particularly the Buscema segments. Some very Kirby-esque cosmic sequences. Plus you have Neal Adams' segments. The 'chapter' with Antman navigating Vision's innards to diagnose him is quite something (it also reminds me of Wilson's work on Rogue Trooper with the rogue AI system).
It is easy to see why this tale is so highly regarded. It is not perfect to be sure but there is an awful lot to commend it. I don't know about others but I find with Marvel that there are absolute gems at times, albeit few and far between. Personally I would put it in that category.