I simply cannot recommend it strongly enough, a proper slice of paradise. We stayed in Railei Beach Club (i've reviewed in TripAdvisor), where the magnificent Railay West Beach is your front garden effectively. You could easily laze away the days there, but walking or kayaking to Tonsai or PhraNang beaches, climbing up to the magnificent viewpoint (get ready to use all your limbs for that one), the sunset cruise and other trips are on offer.
I also enjoyed the restaurants and bar scene - enough of a selection for variety, but not over-run with them. Railay East has a more uptempo scene with fire shows, boxing going on, and a defined strip of bars. West, with a decent selection of restaurants on Walking Street is calmer, though for my money Bamboo Bar was the best of the lot (not listed on TripAdvisor, my review still awaiting approval!) and Kohinoor great for Indian food.
Happy to answer any questions you may have. Video link below.