We stayed at the Krabi Sands hotel...
We stayed at the Krabi Sands hotel from March 17-23 2007 and have to say: EXCELLENT! If you are looking for a really quiet place, away from all the main tourist spots, that's the place to go!
The staff was really nice and helped out in every way they could. I don't know if it was the time of year we've been there, but there were just 5 to 10 other people at the hotel, so we had like a private pool.
Like other people said, it's situated quite lonley, altough the Sheraton hotel (with a great beach!) and the Andaman Hotel are in walking distance.
We rented a motorbike at the hotel (for 300 Baht a day) and explored all of Krabi.
I personally would recommend to rent a boat (1500 Baht a day - for the boat, not per person!!!) and go to Hong island. It takes about 15-20 minutes to get there. Be sure you don't forget your snorkeling gear like we did :-(
Summary: If we come back to Krabi one day - AND WE WILL!!! - we would stay at the Krabi Sands again. 100% Recommendation!