After years of one party rule, Mexico is still pretty partisan. Fox is from the PAN party and he ended the 70+ year domination of the PRI party. So... if you talk to someone from the PAN, he was a good president... from the PRI, or one of other emerging parties, he was certainly imperfect.
I think he was a good president... from my gringo perspective. Mexico has suffered from the lack of a middle class. Fox created a system and demanded that 250,000 homes be constructed and sold to Mexicans. They are small homes in cramped neighborhoods, but they do have financing, so buyers can now buy on credit if you have a job. It's like withholding, and part of your payment actually is paid via money collected from every paycheck. Before you could only buy if you had cold hard cash.
Most years, they built over 500,000 homes, and a new middle class is growing strong. The next president following Fox, the current president Felipe Calderon, has continued this policy. It's good business and very good for the people. Once you start buying a home, it is the first step toward taking an interest in your neighborhood, the area schools, crime, and local politics. That's a good thing.
Since Fox came in there has been a lot of interest in local politics and the campaigning... it has been fun to watch. Previously only the PRI had any influence or power... to get along you went along. It was corrupt and ugly even when they wrapped a pretty ribbon around it.
Fox was educated and corporate trained in the US, considered pro-business. The PAN more closely represented our Republican Party... the PRI a liberal Democrat Party. The third party gaining prominence in Mexico is the PRD... a more liberal, progressive party. The PAN has won two consecutive presidential elections, and the majority of governorships, so its free enterprise, pro growth policies have been popular. Not overwhelming... but popular.
Whatever the political party aspects... what FOX did was good. He was the right person to break the strangle-hold the PRI had on the country and lead it into the future. Without his victory, the corruption would have continued. The drug cartel war going on today is because Calderon has pushed to control or end the official corruption and drug cartel influence. Again, whether he or Fox were 100% correct, they were the president who stepped forward at the time and place when history placed them in the line of fire.
Mexicans are still partisan, and the PRI's former position of control aligned them with the labor movement... which is strong and fiercely partisan. Nature of the beast. So how Fox is viewed may engender a partisan approach.
The PRI has regained its balance and the PRD is coming on strong... actually came in a close 2nd to Calderon. The next election promises to be a real three-way barn-burner. No matter who wins, it will probably be a necessary stage in Mexico's competitive political picture.
As a foreign resident, I can not take an active part of any political activities, in particular with party politics. But I have enjoyed being a keen observer. It's fun to see the similarities and differences.
Hope this helped!
I am a north American living in Mexico.