I'm not sure that DA Support would answer this question but who knows, maybe they-ll supprise me.
I believe the OS you use is a personal choice, you need to choose an OS that you feel comfortable using, choose one where you know you'll get support for an extended period of time because you'll probably not change the OS in a hurry once you have customers on the server.
A lot of people (including myself) have chosen CentOS but an equal number have chosen FreeBSD and yet others have chosen FC and other OSes. Make your own choice, at the end of the day the best OS for you is the one that you can use and keep secure and up-to-date.
Regards,
Onno Vrijburg