It won't sound too bad if it's done right. done right meaning quality TIG welds with no exhaust pipe rattling. However, a leak in the system does sound like crap, I had one. Getting a straight pipe is not for the show car. It is strictly for performance and only a select few appreicate it's functionality. Also, few actually spend the money to do it right.
It's going to sound horrible. I once had an exhaust leak on my other car, so air was coming straight off the catylic converter, I thought it sounded horrible. You could try it and see if you like it, but i didn't.