Been there, done that. This is my take on PW. The kids are busy first 2 to 3 days and you don't see them out much. After that, you will start to see them flock in masses to the parks during late afternoon or early evening beginning on Tuesday. By this day it seems teams are being eliminated and then they just spend time at the parks.
Once they're out they travel in whords and you can't miss them. They will primarily be at MK so if you're there early it shouldn't be too much of an issue. By 2:30 they were out in full force and we simply went to another park (epcot) and had fun there.
We hardly ever saw them at other parks for the exception of DHS where they were there early evening for the awards ceremony; I want to say it was around Wednesday or Thursday. They are gone by Sunday morning when they check out the following week.
We now plan around them and are happy, for the exception of this year when FD was extended and now runs right into our supposedly quieter dates (12/17-12/23).
So much for the slightly lower crowd levels and we can kiss quieter restaurants goodbye with the massive overcrowding that accompanies FD events.
PW is not a bad thing, however note that if you want FD you'll have to plan around as I believe the PW dates are blacked out for FD. In general, if you arrive during PW week it won't be that bad as long as you get your fix of MK on the first 2 to 3 days of your visit. Once you do that, then you can go early the rest of the week and then park hop.
At the resorts, we did have problems with noise, but we ended up complaining and getting comp'd for that. Ended up getting 2 days free for a 3 day trip then continued to AKL. If you stay away from the Value resorts, then you should be fine. I remember 3 years ago when a whole team got rowdy and Disney ended up kicking out several PW kids and their chapperones on Saturday night right before they left. I was glad to see Disney not take any kind of crap from rowdy kids and especially grown ups who were supposed to be supervising the kids. I was glad that Disney was there looking at the interest of all of the other guests trying to enjoy their family vacations.