Only for some of us is it already quiet enough. A .22 caliber rifle like the M&P is still at least upwards of 130DB. I hate that I live in california because I'm a musician that loves shooting, but I've already begun to damage my hearing, and seeing as my career depends on it I cant be around loud noises any more. Seeing as how I love shooting and AR-15 based platforms, and my 15-22 for that matter, I'm going through extra lengths to make them as quiet as possible. And a silencer bringing the .22 down below 110DB is brilliant, especially with hearing protection and a can. Then I could shoot all day, with minimal cost, no worry, and maximum enjoyment. But long story short, I'm already looking in to setting up a trust in arizona with a permanent address and keeping the silencer there, and only shooting in AZ. (around a 2 and 1/2 hour drive for me), which is well worth it to protect my hearing and enjoy shooting and training with such a wonderful weapon.
Thanks for all the input and advice so far guys. I Really appreciate it!
-Charles