Which new OS should I move too?

I need a new OS on my main box. Something technical that will give me a more in-dept knowledge of the technicalities of Unix and Linux.

I'll be attending a grey hat boot camp in a few weeks. What should I compile?

I'm a newbie to network OSes and the only Linux I use extensively is Ubuntu.

>>20
BSD is designed. Linux is grown. Perhaps that's the only succinct way to describe it, and possibly the most correct.
As much as that sounds like a derogatory comment in Linux' direction, I really have to agree. Linux development has been very... contextual for most of its lifetime. Miraculously, it has been done very well contrary to expectation.