Make sure that you make your evaluation based on facts from people working for, or worked for one of the airlines. Rumours from outsiders are rumours from outsiders.
Therefore, on this thread I cannot say anything about Ryanair, easyjet, BMI or Buzz. But I did a contract for Go. they have a new ops management team (the former chief pilot and training manager went to BWA). The new training manager I know as a solid professional. Sim and Line Instructors professional and team minded. Rostering Manager "bending backwards" to accomodate your requests.
On the other side, no crew transport at STN when the sun is shining, and no crew meals.
All in all a good operation, in my opinion.