Hello,
The clubs were very nice. The checkout / checkin process of children was excellent. Basically each age group has it's own itinerary of scheduled activities that occur sometimes in the clubs, and sometimes in other parts of the ship. When you want to check them in or check them out, you just go to whereever the activity is and check them in. It's all computerized. The only time you can't check them in/out is during 'transition time' which is when they are transitioning from one location to another, and during a few shows. They also can take them to lunch and dinner if you choose. The clubs are large enough too. At night, if the adults want to take in some of the adult activities, we checked them into the lab, sometimes from 10PM - 1AM. They usually have movies and more quiet time during that time(at least for the 5-7 year olds) but the 8-9 year olds could play games, computers, etc. The staff was really good and there was plenty of staff members every time I was at the club.
My sons did not attend the Goofy activity so I can't speak to that. Some of the activities actually did have characters attend, but not all of them. Yes my boys were in separate groups. Also, my kids seemed to be more interested in attending the clubs when there was a 'main event' going on. When there isn't a main event scheduled in the oceaneers clubs, then it pretty much free play/activity time in the club, which includes computers, games, etc.
Overall, I would rate the clubs pretty high. We have cruised before, but never on Disney, and we would definitely go again on Disney.
Lot's of character appearances throughout the ship, each day. They keep a schedule in the navigator, and a detailed schedule on a chalkboard in the atrium with which characters will be where and when. Generally, we thought it was easier to see characters on the cruise than at the parks. It was very organized. Whenever there is a character appearance, the ship's photographer is there, but they will also take pictures on your camera too.
Hope this helps. Let me know of any more questions and I'd be glad to help.
Carl