I got my first stamp at the beginning of March of this year. I got a .22 suppressor and I cannot believe I waited so long to do it. I submitted the paperwork on September 1, 2011. It was approved February 29, 2012 (I thought that was kind of a neat approval date). I have had so much fun with it since then that I cannot even remember the wait. Shooting subsonic .22 LR out of my Savage bolt action it is movie quiet and a huge amount of fun. Out of my threaded Ruger 22/45 it isn't movie quiet, but still hearing safe, and also huge fun. I first shot a suppressed gun around eight years ago, and I have a friend with a suppressed 9mm AR that I first shot about six years ago. I have no excuse for waiting as long as I did, but doing a lot of reading on these forums pushed me over the edge, that, and having a Class III dealer in my town.
Back in late December/Early January I submitted three more forms, two for SBRs (9mm and 5.56) and one for a 9mm suppressor. Assuming a similar wait time to my first stamp I should have all three back by the end of July, perhaps a little sooner (here is hoping). I have more paperwork to send in now, just trying to find a spare $200. Big warning, NFA can become addictive.