Welcome to the forum GringoCarlos and Martin Pierce.
Carlos - how was the mail/magazines/packages from the U.S. service in the other Latin America places you lived for 6 years?
Martin - fellow Pacific Northwesterner here - given the places in Mexico you've already experienced, what are your requisites besides "less gringo area than Chapala"? How close to quality hospitals, larger shopping choices, beaches, cultural activities, airport, etc., do you wish to be? What kind of climate appeals the most to you?
I know many expats desire NOT to live amidst large populations of other epxats; however depending on your grasp of the Spanish language, access to such a group can be a good support network initially for assistance with a lot of "every day living" tasks from licenses, paperwork, local laws, local businesses, the ins and outs of adapting to a new country, town and neighborhood as you get to know where everything is and get to know the community. As Pedro mentioned you can find places to live at "Lakeside" and not feel immersed in expats, and still have access to that network should it be helpful, especially during the transition period.
There are places in Mexico that have existing "gringo enclaves" and others that have relatively few, if any, Americans or Canadians and of course in the latter, rents and real estate prices will be lower, but you may or may not find that the infrastructure of services is not what you require.
It's great that you've already gone to several places to experience those locations - what other places are on your list to check out? Cuernevaca? Puebla? Merida? Todos Santos? Queretaro? Jalapa?
Cheers-
Katie