I remember seeing these units in an electronics industry sales brochure and thought: that's a very simple concept, designed in a very simple way, fragile in their electronic environment and implemented with a naieve assumption about their intended environment; but built into an expensive and robust system which is quite out of proportion to what they actually do (and even more worrying, what they migt not be able to do).
Or in plain english, a Good idea, badly implemented.
But I never realised that NR had bought them and had rolled them out across the network.
To be fair, though, surely a system which was even simpler to set up but much much more immune to error, could be a real benefit in reducing posessions or increasing the fulfillment of minor works, or am I wrong?