TTI exhaust, is it worth it??

i hear what you guys are saying and thanks for the heads up. I would be going with their 2.5 inch x or h, not sure yeat, but i'm thinking is that half inch will really make that much of a difference??? I'm hearing different things though, some guys say that they're great and fit nicely all the way to the back of the car and some that absolutly hate it, i know not every car is the same but there seems to be a lot of inconsistancy. Thanks though guys it is much appretiated!!!