This is an interesting idea. I’ve got dozens of SD disks that I can get rid of and around 250 HD/BR disks that I’ve bought, would 'loan out', but would eventually like back. I’m just thinking off the cuff, but would anyone be interested some sort of disk trading thing, or would that be more of a PITA than what it’s worth??

I'll speak for the Hellboy BR CV. I've got in SD, but not HD yet.