Is there a report or dashboard widget where I can track the total number of devices connected at 2.4 GHz vs 5 GHz in a given day? I feel like it is staring me in the face but I can't see it.
In the "Network Settings" tab of the DashBoard there are a number of widgets, such as "Unique Wi-Fi Clients over Time", that will show how many 2.4 and 5 GHz clients you have connected.
The "Active Clients by Radio Mode" widget will give you the specific information you're looking for. Pie chart with percentages, and then mouseover for raw totals.