I've been several times at the Hilton Waikiki and always love to return. The location is a little outside the center but everything is in walking distance: shops, restaurants, the beach.
The rooms and bathrooms are small, but modern. Everything is clean.
The executive lounge is not too fancy but the choice they offer is ok.
The pool area is very nice, however it is often windy and there are (because of the winds?) no umbrellas.
Everytime I return to the hotel, I learn that they improved something.
I absolutely like it.