Well Ryan, I only took it for about a five mile test drive just to make sure everything was buttoned up properly. I haven't driven it hard enough to notice a difference in the light weight driveshaft yet, but it's a one piece unit, as opposed to the stock heavy two piece DS. This makes me more comfortable when doing track days with the car. And I expect that the engine will spin up a little faster with much less rotating mass to turn.
As far as the Blowfish Racing shifter bracket goes, I liked it on my short test drive, but for anyone who says there's no additional NVH, they are smoking crack! As you probably already know, it basically "mounts" the shifter to the tranny rather than the body of the car, so there's no way to NOT increase NVH. I do not think it will be untolerable, though. And in a weird way, I kinda liked it, well, because RACECAR, of course! LOL Time will tell if it is OK for a DD.