that one is hard. I have 3 bio kids, the youngest is 20 months old. if I we were going on a long drive vacation to the beach, it would be tempting to leave an infant with someone they knew. I would probably take him now, but a year ago it would have been nice for all of us to have him stay home.
I guess if the respite person is someone the baby knows and enjoys being with, it wouldn't be bad. I am one of those parents who takes vacations with no children
I agree that sometimes what we enjoy, small children do not enjoy and see as a "vacation."
Good luck deciding.