blog address

A set up a few blogs with sub-domains i.e.
http://lottery-scams.the-world-in-focus.com
but the real address is http://the-world-in-focus.com/blog5
What I would like to know is, is it of best to change the WordPress address (URI): in Options from http://the-world-in-focus.com/blog5 to http://lottery-scams.the-world-in-focus.com because I use the sub-domaine for listing on directories and links etc.
Thanks in advance,
Richard