Dont know if you are directing those questions to me, but if it is, ...
Don't know how loud mine is compared to yours/others. I put on stock mufflers with the Xo2 downpipe and mid and y-pipe. but sound weird, so I put the Xo2 mufflers on, and straightened the mufflers a little bit.
I dont think i have exhaust leak issues anymore. Maybe it was just the sound of the turbo?
I am not sure what area you are talking about. I got off onto countyline from I-25. went straight to go to the costco. then took yosemite. I think it was around 5... not to sure though.
here is youtube of my with xo2 turboback. dont know how much it will help to determine how loud it is.
[ame=http://youtube.com/watch?v=pOLTsrxw9PY]YouTube - XO2 turboback take-off and driveby[/ame]
(it'd help if i actually put the link in...)