Isn't that like a Mr. Rothchild asking, Buchenwald or Auschwitz? I guess each would have its advantages or disadvantages over the other but is it a choice you really have to make or want to make? I don't know much about Mesa but from what I read it has its problems.
The 5K that G J is offering will be lost in a few months by the lack of work rules. If it takes you 20 days of working to get 85 hours of credit you might get 95 - 120 somewhere else. Am I correct on that Skywest and other guys?
Send me a PM and I will send you information on G J from the former regional manager's perspective as well as that of others, and you can add that into your decision tree. If West Coast is important to you then G J does not have anything for you. If you are a Northern WI or Minn guy and like the cold then you might like G J since most of its flying is in the north.