I use them and save 10% by doing so. It really isn't a hassle at all, in my opinion. I buy them through AARP, they are emailed to me, I download the certs, then email each to RCI at the email they provide along with my booking and cabin numbers. It takes about 10 working days for the credit to hit, so you cannot wait up until the final hour to go through the process. They are only good towards the price of the cruise and not OBC. If you reprice and then are owed money but paid primarily with the certificates, they will refund to the card you used to make the initial deposit.