Hi bmatthews7531, absolutely new to Unix?, ok, so you must try a Live CD. I think, it's my opinion, that this will be the best first contact with Unix/Linux, due it is a Live CD it's the faster way to startup a Operating System, and you can break nothing
. Also with this kind of distributions you can learn what are the possibilities of this kind of Operating Systems, I will not answer you what are the pro and con because I'm sure that you must be the person that must find the pro and con, I think that this is the best and only way to see this issue and learn.
Of course, if you want to investigate deeply you can start with any of the long list of Linux distribution, perhaps Ubuntu, openSuse or Fedora, and finally, if you want to run with a professional system you can try the Solaris family, OpenIndiana, Opensolaris or the Solaris itself.
About the C++, you can be sure that any C/C++ will be faster in Unix/Linux, it's not necessary to say nothing more about this point.
And finally, ok, I will answer you, Unix/Linux is faster, stable, open in the most of the cases, robust, scalable, efficient, friendly, cool and a lot of things that you must see by yourself.