I've taken the LDB boat from EIS to LDB a couple of times. From the airport there is a short ride in a van to the boat and then the boat ride over and a buggy ride to check in. Very relaxing after a long day of flying especially late in the evening after the last plane arrives at EIS.

I like Little Dix and while it isn't perfect, if your expectations are tempered for the Caribbean, it can be quite enjoyable.

Last time I was at Biras was last year for dinner and drinks. Necker was a half day visit about ~5 years ago, through a special arrangement.