I just won my first attempt at the Globel Crisis camapign, and I did it in just four game-years:

I am skipping the exhaustive campaign description this time. Here is the short version:
This may not seem like new news for regular GC campaign players. Until now all of my SR2020 games have been in the World 2020 campaign and these have all streched out for over a game-decade. So I don't know how long the average GC campaign lasts.
A caveat - I have modded a CVP/Regional interpretation of the map that reduces the game's region count from 184 to 125. I did this by merging all of the tiny regions into surrounding larger ones. I figured out how to transfer this mapping info from my modded World 2020 campaign and apply it to Global Crisis, so I had sixty fewer regions to deal with than most of you do.
What I really appreciated about the GC campaign was how the other regions helped me out by attacking and conquering each other. I just love it when that notification comes up in the top left part of the screen, announcing that some region has been eliminated from the game - and I didn't have to lift a finger.
I am going to try the Shattered World campaign next.