Has anyone had a chance to use Linux backtrack 5 r3 on their machine? is it better than the latest fedora? and despite the things I've heard about a lethal worm being on anon ISO which is the most reliable (security wise) and will allow me to encrypt the majority of my data?

You don't need backtrack. It is not for whatever you're trying to use it for. Backtrack is not designed to be secure (it's actually very insecure) and it is not optimized as a full-time os.

Kali Linux is now the one who we use because the same company that did Backtrack but they left backtrack and start updating kali linux