Restrictive Mufflers

Anyone post this yet?
very nice side by side with lots of tests for 1/4 mile, hp, noise:

http://www.pontiacstreetperformance.com/psp/exhaust.html
Nice that it's tested on a big engine which would need to breath lots, not a mustang with a 5.0 (no offense intended to rustang owners) so I find it more applicable to a BB Mopar scenario.