Stayed there in 2002. The rooms are very average (without AC) as specified above me, but they should be enough for those who don't plan to sit in the hotel all day/night long.
Lux-mar isn't a walking distance from Playa Den Bossa (Bora Bora, Space) or Ibiza Town (aka: u need to drive/use public transportaion), however its located near a shopping area and the fabulous beaches of Figueretas.