I've worked at both. Why I left Mesa for Envoy...

1- no affordable health insurance option at Mesa. Basically, no insurance.
2- pay so low it's not worth getting out of bed. By the time you factor in airport parking, airport food costs, hotels, tips for van driver, etc.
3- demoralizing hotel standards
4- Johnathon Orstein goes out of his way to antagonize and belittle employees.