I've had my C & R about 2 years now and have saved hundreds of dollars in FFL transfer fees alone. When you factor in the sizeable discounts you get from Brownells and Midway, the benefits just multiply. I am a collector of Mosin Nagants and Mauser rifles and with the C & R can get these guns for about 1/3 to 1/2 what I would pay at a gun or pawn shop. And it plain just does my heart good to see that BBT showing up with another long cardboard box.
Now the downside is that the ATF can inspect your collection and bound book once a year, if they choose to. However, I've never heard of this happening, though I'm sure it has at one time or another. And as far as being 'on the list' is concerned, if you've ever bought a handgun you're already on it. And for that matter, as long as FFL's have to keep 4473's forever and a day, the boys in black can always go that route to see whose a gunowner anyway.