I just wanted to post it up in case anyone else would be curious in the future. I gutted the cat on the stock pipe today using a 1" spade drill bit. It had that hard, more metallic material that was difficult to remove.
Difference in sound is hardly noticeable. I really cant hear any difference. So no worries in that department. butt dyno approves, however I am sure there isnt a difference in reality. good mod considering its free, cant really think of any foreseeable negatives, and pretty darn easy to do on the bike.