Actually, there are 2. The Lagoon Tower and the Kalia Tower. I've stayed in both, and both are very nice. The rooms are spacious and nicely furnished. The balconies offer great views. I wouldn't recommend a studio in the Lagoon tower though since the studio doesn't have a balcony. There is a free laundry on each floor, but not in the units. They have just completed a major renovation of the Lagoon in front of the Lagoon tower. I haven't seen it yet, but I've heard they did a great job. There is ongoing construction of the new Grand Waikikian Tower at the resort. It is a very large resort, and besides the timeshare units, also has 4 other hotel unit buildings. The Lagoon tower is all timeshare, and the Kalia tower is a mix - about 1/3 timeshare and 2/3 hotel.
You can go to hiltongrandvacations.com to view photos.