The ONLY people that think Two Mothers is a good exhaust are the ones that have never had anything better...
I always hear "I've used Two Mothers on my last 10 bikes & they are awesome" Well Gee if you have never used anything else I guess that makes it easy for you to choose huh... Ask anyone that has owned a Two Mothers product & a premium exhaust like Sato, Arata or Moriwaki which one is better & see what their response is.
If you want an opinion it helps to get it from someone with enough experience with all brands to add some credibility to their statement.
I wrote an article on exhausts for my RC site. Disregard the RC specific info & you will find that most of the info rings true across the board.
http://www.rc51.org/exhaust.htm