I found five of these in an old cupboard I was asked to clear out in a school I did the IT for.
I checked what they were (they were rebranded, but they were precisely just a Psion Series 5mx with a certain software card in them for educational use), nobody had ever used them for anything, and I asked if I could have them. They were only destined for the bin, so they said yes and I took them home.
They're a great piece of kit. I would have killed for one when they were actually the state-of-the-art. I ended up selling them off on eBay for about £30 each when I was short of money a few years later, so they were still popular and useful to someone (aren't they used for stock control and things quite often still?).
They knew how to cross the barrier between "entirely new technology", "sensible way of working" and "converting people from paper records" perfectly. I fear that any revival would lack that kind of knowledge and design skill entirely.