Max fab will probably be better, but Needswings will give you more power when it is open. Just like having a 3" exhaust but without the cost. It is loud as hell. I got the one with the Cat and love it. The catless one will sound better though when the cutout is closed since the cat restricts and cuts down on sound.
dropped a 10th and gained 2mph with BDJ's 3 inch dump setup with muffler...and on top of that it sounds awesome...but thats a whole exhaust, just thought id throw it out there. i was thinking of getting a cutout myself and im happy i went that route...though it is kinda loud even with the muffler...i always set off my neighbors car alarm when i start my car in the morning...lol