Low Cost Mexico Airlines- Yay or nay?

Viva Aerobus, Volaris? Are they okay or should I do Aeromexico? Cost is less than $50 one way Cancun to Mexico City but more concerned about safety than cost, of course

They are very very safe, but be prepared to have (potentially) a very delayed or cancelled flight. They tend to over sell and people always complain and swear never to take them again, but keep using them as they are incredibly cheap.