When I was trying to choose an exhaust I found there weren't enough video comparisons so I made sure to add one more. It's just recorded with a Sony NEX5n camera but I did some editing to help illustrate the differences.
This is the exhaust I installed: CBR250R M-2 Black Series V.A.L.E.™ Slip-On Exhaust System (2011-12) - Polished Aluminum Canister
Photo album: http://www.cbr250.net/forum/album.php?albumid=207
I'm really enjoying it so far. My next mod will be the Yoshi fender eliminator and a brake light modulator.