For the guy trying to decide whats better Ethihad 320 or Qatar 330.
It doesnt matter to me were you go, but choosing Qatar over Ethihad will be the biggest mistake of your career. You cant compare citys, even though lots of Ehtihad crews living in Dubai. Come visit both citys, come visit the substandard housing in Doha for crews, plus you get 14,000AED for housing at EY compared to no option but company slums here at Qatar.
Anyway its up too you, but do your research if you actually have the option of choosing.