Besides that, I developed powerful skills by using GNU/Linux which would be lost by using another completely different OS.
What "powerful skills"? Obviously this won't convince you, but I *presume* you're talking about CLI stuff like scripting/programming/regular expressions, etc. You can do all of that in Mac OS X too, with 'real UNIX' alongside the GUI.
What part of "using another completely different OS." didn't you understood? :P
OSX is similar enough I should be fine with it, even other *BSD flavors. By powerful skills, yes I was referring to CLI, scripting, etc.. AND also being able to patch up software as required, even the kernel (yes I do have drivers and patches accepted in kernel.org, I'm not talking it out of my ass).
But to be honest, I'm really tuned into Gentoo Linux - sometimes its painful to work on anything else. : ) That's why I have Gentoo boxes everywhere, at work, in the laptop, in the server, *heck* even inside the little Intel NUC at my parent's place (they love it). At some point even inside my router :P