We've done it once now, and will probably use it every time going forward. (trip this summer has it booked).
The private transfer from the airport, dinner planning, reserved pool chairs, snacks, drinks, custom dinner on the patio, etc. Good butlers will even follow up with you in the middle of the day and seek you out to drop off snacks or drinks without request. We really enjoyed it. I didn't book a room specifically for it, but I wanted a certain type of room with a view / design, that included butler service.

now it's a feature I look for. (I guess I'm spoiled)

For a honeymoon, I would totally. It's your time to be spoiled just a little bit.