Have to chime in here-Camp Snoopy is awesome for kids! We spent many great days there when my DD13 was younger and now we take my Dnephew 4.5 and he loves it! There are so many rides for the kids.
Were you thinking of doing it when you go to DLR in 3 months? If so, that's the perfect time to do KBF. No crowds, literally. You'll have the place to yourself. There have been times, off season, when my DD did over 25 rides in one day, mostly in Camp Snoopy. After she got older she and I did 26 rides in one day and left before closing because we were all ridded (sp?) out!
KBF always opens at 10 and closes based on season. During off-season they close at 5 or 6 but that is plenty of time to do all.
Besides Camp Snoopy there are the rides that make KBF unique. Stagecoach, Calico Mine Train, Log Ride and they have bumper cars that allow you to actually bump into each other. Pretty fun! When it's not crowded they may let you ride again without getting out. Actually this can happen on many rides when there aren't many people waiting.
And for the bigger and more adventurous in your group, Xcelerator it may hands down favorite roller coaster!
And of course, there's Mrs. Knott's famous fried chicken. Yum!