I'd first start with letting the DLinks find their own channels. They do their own search for unoccupied channels and they are generally better at it.
Then examine the DS logs for lost or delayed packets. The logs highlight problems very nicely. If you see much of anything, then try setting your own DLink channels.
Things to watch out for include other APs and non-robot network traffic in the area where you are running. Letting the DLinks search on their own may avoid some of this.
There are several alternative network topologies (
Robot IP Network Variations ) you can consider using from running just one or two robots, multiple robots in large group demos, or for off-season events. Just keep in mind that what may work at home may not work for a demo at a local shopping mall, so be prepared with alternatives.