add me to that list of those who agree with how well Juli described it, and how Jan feels about it.
Think of ATP as a city, and the different forums as neighborhoods. We hang out in our own neighborhood, and have a block party here we call the porch swing. The SandBox forum is a city-wide block-party. Personally, I'm more comfortable with the smaller sub-set. And it's one conversation (albeit a huge conversation) as opposed to multiple threads like the Sand Box has.
So I come into ATP, drink my coffee and visit my friends on the porch swing, and then move onto the other threads.