Hi Sharon. We were on the Summit Oct. sailing. It was truely fantastic. There were 3 formal nights, 13th, 17th & 20th (I think...one tends to forget all about days and dates when on holiday.) There were 4 of us traveling together and in lieu of taking the excursions offered by celebrity we opted to hire a car and driver at each port for a more in depth tour of each island. This worked out very well, though I did hear the Jolly Roger cruise from Barbados was a hoot. St Lucia was most difficult procuring transportation as one is totally bombarded by offerings when you step off the ship, but is still managable. On St. Thomas do take the trouble to go to St. John and visit Trunk bay...so beautiful and wonderful snorkleing...good lunch on the beach as well. Again I would arrange this on ones own. I'd also save my shopping for St. Thomas. The shops just near the ship house as good a bargains as downtown with out the hassle of keeping up with your purchases.
Have a great time and bon voyage, J
p.s. I would definately recoment springing for the Persian baths premium while on board. It was $100 for our trip and so worth the money.