And yes by the way they do rob top end horsepower ( less than 3 hp at the max of the bike where few people go on average) because they close slightly in the top of the power band for emissions. But gain torque on the low end( where every rider will put the bike to test daily) Knowing that doesn't make them dumb to have or anything else. You can simply change the ecu settings to get it open but most people won't spend the money when a servo buddy is so cheap compared to ecu modification. The bikes have more than just a butterfly valve in them which can aid in emissions and sound but the soul purpose is creating back pressure which keeps the air fuel ratio right due to internal back pressure by external methods. Sure the valve can assist emissions etc but not there sole purpose. Have you not bought something that was supposed to be used for something but instead used it for something else. Also the link you attached was by a company selling exhaust servo eliminators. Have you ever heard of false advertising? Why do infomercials sound so good? Are they all lies ? No but stretched versions of the truth to coerce you to buy they product. I personally have tried the exhaust with a servo and with out on my 06 r6 without the catalytic converter. The bike around the track with the servo was an average of 1:15:53. And without was 1:17:27. And this was done over period of two days where I tried the exhaust both on and off on both days. Read what you want determine what you want but the servo kept my times better. Did I notice the servo doing work? Only in the back stretch of the track and in the slow curves entry and exit speeds but not at all anywhere else . Over all top speed wasn't slowed or quickened but speed was obviously enhanced. aftermarket exhaust remove the exhaust valve knowing that other modifications will be necessary such as a power commander,air filter, possible timing changes etc when u do those things your essentially providing the ability to have the proper air fuel,ratio without the back pressure. Simple as that Decide for yourself which way you wanna go twisted throttles brings me smiles