Wireless would be a useful technology for my setup as well, but I hesitated to add that element to the mix yet. I have had two i9900 on a wireless network and they printed fine. One problem was (they're now hard-wired to the network) that the utility was unavailable via WiFi.
I was connected via Apple Airport Extreme to Apple Airport Express with the printers connected the Express via USB 2.0. Mac OS X...
So, printing was okay, maintenance was not (for the i9900s). I have not tried it on the iPF5000 yet because the printer is physically located at the edge of my wireless network range and I need to set it up with a WDS relay to widen my coverage for a fair test. I barely have WiFi available at the printer's location and it's spottiy. Coincidentally, I need to expand the network anyway and there will be an Airport Express installed near the printer anyway, so it should be easy to just plug the printer in to it and try it. I've not had time to work on it. Still working on getting acquainted with the printer and time has been too limited.