I stayed at the Reef for business, but enjoyed the location for pleasure as well. The rooms are well appointed, and the location is wonderful. The lower level lobby is one large indoor/outdoor area where the registration, bell hop, concierge is located, along with the typical tourist shops (jewelry, Hawaiian crafts, wooden items, clothing, etc).
My room looked west toward the Army Museum and green, but couldn't really see the ocean. The pool is typical size, not viewable to the sea, but does get good sun during the day. It is located between the hotel and the next one, so the sun doesn't shine on the pool all day. They have good service at the pool from the Kani Ka Pila grill, at reasonable prices. At night, the grill hosts local musicians for entertainment and karaoke.
I love the location in downtown Waikiki. Within walking distance are many, many shops, restaurants, art galleries, malls, etc. Street musicians and performers are just down the road on Kalakaua Ave. There are also a number of parks where you can stretch your legs in the sun.
For beach activities, the hotel rents jet skis, kite boards and other such items. Diving is not popular right in Waikiki, but not far.
Shorebird restaurant is in the ground floor and serves good food. We had dinner and breakfast there. Their style is self-grill. They have a large salad bar and bring out your entree raw for you to cook on their open grill. If you are nervous about it, the staff will recommend times and seasonings for you. For breakfast, a large buffet is reasonably priced for Waikiki (around $15).