I had one. They are nice and very convenient. But, they can cause you to go broke or into debt. I let mine lapse and haven't looked back. I realized that my very best deals could not come from a C&R, because the seller is generally on line and knows what he's got. Because of that, my best sources are pawnshops. The C&R means you can get good deals on general items from distributors. It also means you don't have to pay a transfer fee to an FFL for a firearm.
However, you also give up certain rights. You must maintain an accurate bound book, which the ATF has a right to inspect (and they also have a right to inspect your collection). Generally, these inspections are painless and often can take place at the ATF office and not at your home. However, you have opened the window and the vampire can come in, if he really wants to. It was worth it for me, at the time, but when I had to log in all firearms I bought, including the many I had to buy on the yellow form (when they were yellow) when sellers refused to accept my C&R FFL.
In any case, I decided it would be better to let it lapse. It causes more fiscal responsibility on my part. However, I still buy on online auctions, but much less on a whim.
In short, the C&R is a convenient, but not universally accepted, liscense. It makes it cheaper to buy firearms as you don't have to pay a transfer, but the very best deals will not likely come from the internet but from local shops. Many of these places are ignorant or view with contempt, the C&R FFL, so you can't use it for that purpose. It has good parts and bad.
Ash