I haven't stayed at that Marriott, so I can't compare, but we go to the Omni once or twice a month and really love it. It's one of the few luxury hotels for $159-$179 a night.
There is a really nice lazy river, takes 10-15 minutes to get all the way around and it has features like waterfalls, cannons, music and it's heated. The current is nice and swift, it's one of the better hotel lazy rivers we've seen. There are two pools, one more kid oriented, huge, with basketball hoop, waterfalls and a slide. The other pool is more adult oriented and has cabanas for rent that include tv's and chairside service (drinks/bar food). There is a bar there too and the whole theme is beautiful, with columnns and fab fab fab landscaping, including a working herb garden to walk through. Did I mention the two hot tubs?
Although you didn't ask, it also has a full and complete gym (better than some YMCA's!), a very good italian restaurant, a deli, another restaurant (ZEN, haven't been), a coffee shop, several other shops, golf, a kids club and 24 hour room service. Throw in a couple robes and the best service I've EVER had and you've got yourself a heck of a deal. In my humble opinion, anyway.
I'm sure with either of these hotels you can't go wrong. Enjoy your trip!
