Amy,
I guess it's all relative. It was crowded, but not nearly as crowded as we had anticipated. I think if you plan right, you can avoid the big crowds.
We generally avoided EMH parks. During the summer, there are 2 EMH parks every day except Saturdays--One morning and one evening. That leaves you with 2 other parks to choose from. However, there are some other factors to take into consideration. For instance, when we went this past June, on Monday AK had Evening MH and MGM had Morning MH. That leaves either MK or Epcot as choices. I chose Epcot because MK is usually pretty busy on Mondays because it is usually everyone's first day at WDW.
Another strategy to use: hitting a park the night AFTER it has evening MH. The theory being that resort guests would go to the park with the evening MH, but the next morning woudn't go back to the same park.
Some will say go to the Morning EMH and then leave by 11/noon to avoid big crowds. I hear this works, but being from the West Coast, we could never make it. It would be like getting up at 4 or 5am.
If need help planning, let me know and I can direct you.
As far as going with a large group, we did very little all together this time. However, I've been with a group of 9 and a group of 13 where we spent more time together. I think you had asked in another thread how big groups managed. I didn't reply because everyone else had such good advice already.
1) Everyone has different expectations--try and plan accordingly. Leave some free time where people can do what they want.
2) Even if you go to a park together, you don't need to stay together. You can meet up for a meal.
3) Your concern about the one family with the kids. I am single. What I did for my cousins who have 2 small children was I had set evenings where I would babysit the kids so everyone else could go out to dinner. When they came back to put the kids to bed I was still able to go to ESPN or DTD to do my thing. Plan that AHEAD of time, so everyone is clear.
4) Expect the unexpected. Be flexible. We always have a daily itinerary, but have learned to go with the flow and be willing to change things. However, still try and have some sort of plan, as someone else pointed out to you in the other thread, nothing worse than standing in a crowded, hot park with 17 people saying " Now what are we going to do?"
5) Kids love the pool. We travelled with an 11, 12, 9, 8 and 5 year old this past June. When asked what their favorite part of the trip was, they all said the pool. Granted it was Stormalong Bay at the BC, but still they just loved being in the water..
I could go on, let me know what else I can help with