I was in the US working on a TN for 1.5 years. At that time, TN's were not tied to the employer. I'm not sure if this is still the case. You just had to have

I was in the US working on a TN for 1.5 years. At that time, TN's were not tied to the employer. I'm not sure if this is still the case. You just had to have a job in the field that you came in on. That said, you couldn't apply for a greencard while on a TN. For that you needed to get an H1B. For our company I was paid the market rate, no different than a local hire.