The airports in Mexico City and Guadalajara have been spruced up so that World Cup visitors would have a good experience.
I flew out of GDL early this morning and spent the night in the Hilton Garden Inn, right in the terminal. The airport is stunning: well lit, bright open spaces, excellent signage, good food options and shopping, comfortable seating with charging stations. They did an outstanding job. They spent about $500 million on this renovation, and there's a plan to spend another $1 billion on a new terminal to expand capacity by 70%. They'll also be adding a third runway. This is on schedule to be completed by 2030.
I flew through MEX in July. It's a huge improvement compared to a year or so ago, but it's kind of like putting lipstick on a pig. The concourse in Terminal 1 is narrow and very long. The gates are only on one side of the concourse, meaning it can be a very long walk, even from one gate to the next. When people are waiting to board, the lines extend well into the walking area, making it an obstacle course to get through. The flooring they used is rather slick; when I walked through, my rubber-soled shoes didn't grip very well, so that made the long walk feel even longer. Terminal 2 was newer and better, but it mostly just serves Aeromexico. I haven't used T2 for a while, so I don't know what improvements they did there, if any.
I understand they also remodeled the Monterrey airport (MTY), but I've never flown through there.
With these improvements, come on down and visit the second most beautiful country in the world (according to Condé Nast)!