I stayed at Blue Dream for two weeks last winter and would stay there again. That being said each of the three kite-centric places to stay have their merrits.
Personally, when I go again....if I go back with a group of friends I would stay with Bob (kitchenettes \ fridges) whereas by myself or just with my girlfriend I'd stay at BlueDream. My friends were at KiteHouse and really liked it there.
Where ever you stay you will likely really enjoy Bahia Salinas area. My recommendation would be to eat at all restaurants and meet as many people. Those who were having the best time in Bahia Salinas were taking it all in.
I was recently in Hood River (event site and White Salmon) and would say that the wind at Bahia Salinas was better quality.
With more and more direct flights to Liberia, Costa Rica, it really is worth a trip to experience this place.