It has led to enormous tradeoffs, including the loss of some manufacturing jobs. On the other hand it has, as post 4 indicates, facilitated trade between the US, Mexico, and Canada, which has led to more purchasing power for many Americans.
How do you define success or failure? The main point of NAFTA was to get more trade going between the US, Mexico, and Canada. Well, that's clearly happened. In terms of whether it helped the US economy? That's too hard to really know. Our economy boomed after NAFTA and has since crashed. But it's hard to claim that either of those things was actually due to NAFTA.
So I'd call it a success because it's made for more trade. But it's impossible to know if it's helped our economy overall.
Is this an essay you want us to comment on? There are definitely some positive factors of NAFTA, as you have mentioned. However, it still means that more jobs will be outsourced to Mexico where labor and materials are cheaper.