While I personally am not a "pool person", I've heard the slide at OKW is good, and you could try Olivia's for a nice relaxing sit down lunch while you're at OKW.
SSR has a zero entry pool, so that may be of benefit for your 6 year olds.
Pop has themed pools, but they are often crowded. Plus you'd need to bring your own towels, value resorts don't supply pool towels.
Those are the only pools I've really even looked at while walking by, except for BCV, but you can't hop there, of course.