Good read but it should be noted that, by changing your exhaust to something like stated above without changing your fuel curve (re-jetted or re-mapped)

While modern cars can handle exhaust changes with ease most bikes (modern PFI and their older carburated cousins) will suffer from a significant decline in the amount of back pressure any given exhaust system has. This is simply because they have no way to adjust their a/f ratio on their own (no pre cat.conv. 02 signal or jet changes)

Edit: Ps. Thanks for that artical

With that being said I guess I should have mentioned that those "tips" are ok if you understand the principal behind it and have the knowledge/skill to adjust your bike to suit. Generally those with the know how/understanding don't want those things on their bike anyway. Lol