YYZ,
I have been to both Cancun Hilton and the HHV. I enjoyed Cancun much more than Oahu. The beach is not all that great at the HHV. Also, the area of the HHV is like a large city right on the beach. Oahu is my least favorite of the islands. Cancun, the prices for everything will be much cheaper. I have an email from Hilton with a promo rate of 120.00 a night in cancun with 20 % off food and beverage. Also, YYZ Cancun is only 4 hours from Toronto, HHv add another 6 or 7 hours.
The beach and pools the Cancun Hilton is great.