My family and I stayed at the Omni from Feb 14 to Feb 19, 2009. There were 2 adults and 3 teenagers ages 14, 15 and 16 in our party. I booked two rooms using hotwire for a rate of 110 USD including taxes per night per room. Before arriving to Cancun, I signed up to their loyalty program called special guest program. By doing this, I got free wireless internet during my stay and free juices (up to 2 different kinds) for everybody in my party every morning delivered to our rooms.
Rooms: We got 2 ocean view rooms connected, one with a king size bed and balcony and the other one with two double beds, no balcony but a table for 4 people, refrigerator, microwave, stove, dinnerware and silverware (Room 2046 and 2046A). Each room has its own bathroom with a tub. Rooms were very clean and well maintained, the only negative is that the water in the shower did not have enough pressure and sometimes the temperature of the water changed randomly. We had one TV in each room with a lot of channels including multiple HBOs. Enough towels are provided and the Omni offers a pillow menu where you can choose different kind of pillows, around 8 different options.
Parking: Parking is free and valet parking is available with no charge. The parking area is very close to the main entrance probably just 100 feet from the main lobby entrance.
Gym:There is a gym at the hotel but unless you are in an all-inclusive rate, there is a fee to use it. I think is something around 9.95 USD per day and only people older than 16 years can use it.
Food: We only had breakfast and lunch at the hotel. There are 2 restaurants where you can have breakfast, la paloma and pina colada. Both offer good buffet breakfast with fruits, juices, cereals, pancakes, french toast, and all kinds of eggs cooked to order. The difference between the 2 restaurants is the price. La paloma is more formal and it costs 270 pesos (~18.66 USD including taxes) and pina colada is 170 pesos ( ~11.72 USD including taxes). Pina colada is in front of the beach and open air. My family and I liked pina colada better and it was cheaper. We had lunch 2 days in La paloma and the variety was Ok, burgers, chicken nuggets and the normal stuff. I payed around 650 pesos ( ~44.82 USD) for lunch including tips.
Pools: The big pools are beautiful and very clean but the water is really cold. They don't heat the water. There is one "hot tub" but the water was not very hot and because it's the only pool with heated water a lot of children use it and it was not very clean.
Drinks: Drinks on the pool cost 50 pesos (~3.45 USD) for a beer, 60 pesos ( ~4.13 USD) for a clamato and 70 pesos ( 4.82 USD) for daiquiris and pina coladas.
Beach: The beach is beautiful and there are waves on it but there are rocks all over the place. It's impossible to swim in the hotel premises. But let me be clear, I walked to the left and right of the hotel for 1 mile each way and only the Oasis Cancun has a small area where you can swim. I checked the Gran Melia, Marriot Casa Magna, JW Marriot, Hilton, Royal Mayan and none of them have a beach without rocks where you can swim. According to some hotel employees, the government is planning to restore the beach by bringing sand and creating a reef in the ocean.
Service: Service was great in all areas. Restaurants, rooms, bell boys, front desk, pools, etc.
Time share people: The first morning after our arrival, I got a letter in my room to invite me to visit the time share people. Just for showing up, I got 5 free drinks and an invitation to attend a presentation that lasted 90 minutes and included buffet breakfast for all my family. They gave me 280 USD in coupons for food and drinks. During the check out process they used the coupons and deducted 280 USD from my bill, only food and beverages, no tips or any other expense like local phone calls or massages were deducted. From other reviews, I was expecting to get a lot of pressure from the time share people during my stay but that was not the case. At the end of the presentation, I just declined very politely and I got my coupons.
Location: Hotel is in the south zone of Cancun. There is a convenience store, a pharmacy, McDonalds, Subway and a Bank across the street. I had a rental car, but one day, my wife went with my daughters to the mall using the bus and they payed 20 pesos for 3 people one way, around (1.5 USD ).
Overall a very good experience.