Pros
Good mission, great people to meet and broaden your horizons, gained lots of skills but had to sacrifice university grades, social life, and literally anything else outside of AIESEC work (not to mention the hundreds of pounds wasted on 'conferences' which involved a bunch of students getting drunk and having maybe one or two external speakers to give an inspirational speech)
Cons
Complete lack of structure. The need to "innovate" means turnover happens so quickly (every year) you don't have enough time to see if things will turn out to be successful. There is a 'cut throat' culture - if you even say anything negative about the organisation you'll immediately get shot down and told to think more positively. There is no space for excuses even though everyone in the organisation is a student. Seems like you only matter if you're on the national/international teams. Complete lack of support and mental health awareness (ridiculous considering the amount of pressure you are put under). And the leadership body can't even do anything because they aren't qualified to deal with these kind of problems. Just a lot of making it up as they go along.