I've been to WDW at the same time as the PW kids many times. Generally speaking, I have no issues with them. I was even at ASMusic with them!! IF there were going to be a problem, that's where it would have happened. But, not an issue. Sure, more kids in the food court and on the bus but that's about it.
As far as kids in the parks go..it's usually only noticible at night. During the day the kids are in competitions. You will run into more groups of kids at night in the parks but I have yet to have any trouble with them. I've actually had much more of an issue with the day trippers in the spring from various area schools and youth groups...those kids were severely out of control!!
I wouldn't worry too much about the PW teams being there at the same time. Try to avoid the resorts they are at and you most likely won't even notice they're there at all.