I've heard that NAFTA provides an easier immigration process for employees in a NAFTA country (Canada or Mexico). How does that work, and what are the limitations and trade-offs of this method, if any?
Unless this has changed recently, this comment is not true.
Unfortunately AFAIK there are no published statistics for TN approval rates.
It might also be worth noting that TN is not a dual intent visa like H1B.
IANAL.