The jury is out....
I've dug the gadget out and got it set up.
Trying it with a cheap USB MIDI adapter I've got in a junk box, it works but the response time is abysmal - play just a three note chord and there is a good chance you hear the notes spread out over half a second...
Updated the firmware, tried various programs and network configurations but it's just erratic.
I gave up and plugged the USB MIDI device straight in to the laptop - and it's still the same!
I only ever used it briefly when I first got it, but I thought it worked OK originally; it definitely does not now.
I don't have anything else with USB MIDI here at present so I can't be sure if the ethernet device is working OK or not.
I may be able to get my hands on a different interface sometime next week..