I like gift registry's. I don't think it matters what sort of wedding you have, people always turn up with a gift. When you send out the invites you can pick and choose who you want to put the gift registry thing in, as only you and your DP know who would not like it.
It certainly doesn't hurt to have one, and if people don't want to use it then that's fine. It helps people who unsure of what to get, they usally appreciate it.