AnywhereUSBs are slower than "native" USB ports and standard USB hubs due to several factors, such as network overhead and a 10/100 Mbit/sec network interface. Because of this, certain applications, where performance is critical, might not be well suited.
1. Ensure the AWUSB is configured for 100 Mbit/sec / Full Duplex, as well as the port of the Ethernet switch it's connected to.
2. Ensure you're running the most current AWUSB firmware (older versions are USB 1.1, whereas newer versions are USB 2.0).
3. If it's possible, isolate this computer and AWUSB to a private/isolated network, in case other traffic on the network is causing congestion.
Besides this, there aren't really any performance "tweaks" or tips that I can think of to make it perform any faster.
I believe Digi is considering releasing a newer model AWUSB with Gigabit Ethernet and USB 3.0 support some time in the future, so that might be worth trying out, if these suggestions don't help, and you're still looking for this solution at that point in time. I might suggest asking Digi Sales about this, particularly if you'd be potentially interested in purchasing several units.