Wow, D, what can I say?
I haven't made the move yet. Still closing shop here in Toronto, but will be there by the end of August.
Moving to Mexico for me was a very personal reason - my father became ill and I want to spend as much time with him as possible because you can't buy time.
I'm an entrepreneur and have a career that allows me to transfer my skills to anywhere in the world. I also have the advantage that I'm fully bilingual, plus hold dual citizenship, so for me to live in either country from that standpoint is easy. I'm not sure how old you are, but Mexico is an ageist (and elitist) country - the most effective way to find work is through connections or to set-up your own business.
I would not recommend moving there and then trying to find a job. In fact, I wouldn't recommend doing that no matter which country you were considering.
If you are being offered a transfer, great, but make sure you have a signed contract prior to moving there, which includes among others: relocation costs, a moving incentive, health care insurance, and a severance clause - many American companies exclude that because in the US, most states operate under 'at-will' employment law, which means that companies don't owe you a thing unless it's specified in the contract. If you've worked for the same company for 20 years, that could be a lot of $.
You also have to consider the tax complications. Worldwide income kicks into effect and the process of filing
taxes is not as simple as you think. A friend of mine worked in the US for 6 months, payed taxes there, used an a CA with international tax specialization, brought back her filing so that she could prove she had paid taxes there, but CRA told her "that's nice, but you still owe Canada $25K in taxes". She's going to court for it, and won't have to pay it, but it's a two-year process.
If you thought immigrants had a hard time finding work in Canada or the US, Mexico is even tougher. You'll have a better chance if you're an entrepreneur - the market is huge and let's face it: multi-nationals wouldn't be there if there wasn't a lot of money to be made in Mexico.
If you're retiring, then, by all means, do it and enjoy. Just remember not to show off your wealth, unless you want to become a target.
Mexico is an incredible country and it can be the land of opportunity for the right person, but do your homework.
Best of luck, and let me know if you need any more advice.
: )
Gaby