We traveled in a group from 06/21/11 to 07/05/11 from the Gurney company, which works from Natalie Tours. We booked the Sumbo / Borneo hotel, located in Cala Millor, a town in the southeast of the island.
Unfortunately they didn't last long. I can compare basically only with good 5 * hotels in Turkey. Compared to them, the hotel is small, but rather big: everything you need is there.