On the practical side, I've shot a black bolt and it shot OK. Wasn't mine and it wasn't as nice looking, but everything fit and the guy who picked it up was for the back of his truck. From the ones I've handled in the store, they need to be inspected well, but that goes for any firearm.
I've been tempted to pick up a black bolt to stash at the cabin, but haven't done so yet. I think they are OK for a shooter if you can go through them, but for a bit more cash, you can get something nicer looking or collectible.