Another Newbie joins the group

Honestly, I am normally a British Virgin Islands traveler, but I am unable to make anymore trips there this year and I NEED a Caribbean fix. Next best option would be Cancun/Playa right?!?!?!
Since I've never been to Mexico, I am looking for some insight. My husband has decided to not join in this excursion so it will only be myself and my 10yr old son. I am looking at the Omni Cancun Hotel and Villas. Can anyone provide some details, thoughts, concerns about this place? Is there enough there to eliminate us from having to leave the resort? Is the beach a good swimming area?
Finally, we are looking to break-up the Seattle fall nastiness (Read: RAIN!) and planning on a mid to late Oct trip. I know in BVI, this is the end of the hurricane season. Should I be concerned with this time frame for Cancun? Looking at 10/16-10/21 OR 10/23-10/28.
Thanks for any and all information!
