Founders Hall is usually a pass-through area for me since I visit Caribou Coffee quite often. There used to be a lot of other shops in Founders Hall, but a great space... the vaulted glass ceiling definitely makes it a nice, bright space and a great place to take a break from the workday.
The decorations during the holidays are great and there's an automated choir of bears that kids usually enjoy.
I've also been here for a wedding reception. They place fabric over the store-fronts and makes for a nice and unique reception right in the middle of uptown Charlotte.
Founders Hall could be considered as one of the "ends" of the Overstreet Mall, but it's still connected to the Omni and Hearst Towers via skybridges. Super easy to get to on foot... I'm not sure a lot of people that don't work uptown know that there is a nice space in the tallest building of the Charlotte skyline.