We stayed here with our two kids, ages 6 and 8 in Aug. 2007. We had a studio with kitchenette. Our room was on the first floor and in close walking distance to the pool. It was very quiet, and I rarely heard any noise from outside or upstairs when we were in the room. This was despite the hotel being fairly busy.
It was definitely a big plus how close we were to the beach. It was nice to just take a short stroll down to the water, and be able to play, swim, and snorkel there. The water was nice and fairly calm. Our kids were able to run in and splash without too much worry.
Plan to catch the sunset from the beach. You get the best view right there from the hotel's beach access.
The pools were also really nice at the hotel. They have 3 different pool areas. The one on the north side has kind of like a lagoon/river sort of arrangement, which is very nice. This pool was always less crowded than the main pool on the south side of the resort. This main pool had the big slide by the waterfall, so obviously it would be the most crowded pool. Then there is a smaller pool area for those with toddlers. It has a big pirate ship that shoots out water and has small slides for little ones.
Kids eat free with each adult meal at the hotel's bar and grill, but we were disappointed with the food. It really tasted like it was just reheated frozen food, rather than fresh-made-to-order. We preferred to take the complimentary shuttle into Lahaina and try the restaurants there. One place we enjoyed and found to be reasonably priced was the Aloha Mixed Plate restaurant behind the Cannery Mall. You should definitely make a stop there at least once to have some local food. We also went to the Hula Grill at the Whaler's Village, which had really good burgers.
I also highly recommend taking advantage of the complimentary shuttles into the different parts of Lahaina. No need to stress on driving and parking!
Overall, we had a great stay, and would recommend the Westin Ocean Resort Villas. I am giving 4 stars only because we were disappointed with the dining options at the hotel. Too expensive for sub par food. However, the hotel is extremely clean, well-kept, and the staff is friendly and very helpful.
Enjoy and aloha!