Removing the silencer will only give you a headache if you ride without a helmet. If you keep your helmet on (and your bike isn't giant) you should be okay. I never ride with a silencer on my '67 Kawasaki and the noise is perfectly acceptable to me as I ride it. Now, if you happen to be riding just behind someone running a straight stinger, then you're going to encounter some pain.
Back in the days when men were men, you would see 501 Maicos being run with no silencer at all. You want to talk about noise, Johasus! And yes, in the '70s when riding was starting to get popular, the noise complaint was exactly what it was today. Track owners and promoters were shutting down tracks, and no one wanted to put on a silencer because it robbed performance. Then, some of the magazines did dyno tests that showed that a good silencer doesn't significantly reduce performance. What they conveniently forgot to mention is that it also has to be looked after a lot more than most people are willing to, so in reality, 90% of riders will lose performance with a silencer. The difference in power for my 250 was insane once we got rid of the packing. It doesn't do much in the way of silencing anymore, but we don't have to worry about it getting gummed up.
Silencers used to be considered a "neccessary evil" by the manufacturers, and they only included one because regulations forced them to. That is no longer the case. On modern competition bikes (two-stroke or four) the silencer is an integral component of the over-all tuned package. Removing the silencer from your bike will
drastically change the wave tuning of the exhaust. It's a complete crap shoot as to what changes will occur to the power curve. In most instances you will drastically reduce the width and rideability of the power curve in exchange for a small boost at the very top of the power curve, not a worthy trade-off at all in my opinion. And the ramifications of riding un-silenced bikes is way too serious to be recomending such to other riders. Nearly every riding area and track that has close across the country in the last ten years has closed for one reason-sound complaints. It's both irresponsible and selfish to be recomending to others that they should remove their silencers.
And removing the packing from your silencer? I defy you to show me a dyno test that provides any evidence whatsoever that it does anything other than
reduce peak power production. In an unpacked silencer, the normal smooth, laminar flow of exhaust is destroyed, and replaced by a very turbulent flow. Turbulence will have the exact opposite effect of what you claim. It will actually reduce flow, thereby reducing peak power. Your bike will perform better with a properly packed silencer. In most cases, when a rider claims their bike makes more power with an un-packed silencer, it's nothing more than a placebo effect caused by the increased sound. Sound does NOT equal power.