I have stayed at the Westin ATL with my wife and 3 kids and they have always been good about giving free breakfast to all of us. The one caveat is that we have booked 2 points rooms in these cases, so not sure if that helps or not to cover all 5 of us.
The breakfast is a buffet style, but is a very good buffet, with lots of hot and cold options and good service.
We always have enjoyed the Westin ATL airport, but it looks like they have recently gone from a Cat 2 (3K pts/rm weekend) to Cat 3 (7K pts/rm) so we will be trying the Sheraton ATL. How is the breakfast and rooms there?