I went with OSM, i have friends who also went there and recently graduated, and are currently going through airline interviews. They say the school is very good, there are no delays, you have the 13 atpl subjects in 3 different phases and also the flying is done in 3 different phases. It is very professional school, has a very good job placement, you can look through LinkedIn of their recent graduates, most of them are already with an airline (transavia, SAS, Norwegian, Ryanair, Wizz air) I start as part of the april class.
If you have any questions I can answer.