That's a good call and I was going to try that, but I had the client attempt a file transfer to another wireless client on a different 100/full connected AP inside the same environment (VERY large manufacturing facility). The results were the same. 43 APs in this large building, all connected to 10/100 switch ports.
One of the switches has an available fiber port that is gig. The client is going to install a copper sfp, connect the AP to that port and use a power injector to get the AP connected at gig/full, and then we're going to test again.
The TAC says they don't have any documentation regarding expected performance results when 10-15 clients are connecting to an AP which is on a 100/Full port.