We were on St Kitts last January. There are more monkeys on the island than people. Don't put your drink down on the beach....they're alcoholics! Just kidding.
Not much to do if you like nightlife of any kind. Looked to us like their was only a couple of bars in town. When we were there the small city (only about 5 blocks square) they call a capital was really dirty. I'll be interested to hear what impact the Marriott's opening has on the attention given to the downtown.
People are very very friendly....and poor!
They make and sell a great cane spirit (basically rum) called CSR. Only sold there and is worth a try if you like rum.
Please post a report after you return!