Actually, I'd have to empasise that reliable behaviour ought to be primary. The best, most intuitive UI in the world is worth nought if the thing freezes up and/or simply fails to make scheduled recordings with unswerving reliabilty.
The experience I had with "training" my elderly female neighbour was far less about the actual workings of the machine (which is a Digifusion FVRT200 - no longer available and never the best UI out there, but hers - and mine - have been utterly reliable), and far, far more about the conceptual move away from the linear concept of tape recording - not having enough room, remembering not to over-write wanted recordings, one activity at a time, and so on; and of using an EPG rather than the Radio Times (etc.) It took a lot of patience to get her to accept not having to rewind, being able to find recordings from the list, being able to delete without concern over the space left and whether it could be re-used and so on. Once you get past this, the rest is pretty easy and/or a matter of practise.
By way of background, this person, used previously to do it like this: put a 4-hr tape in on LongPlay (so, 8 hrs) and start it recording on the ONE channel she felt had the most important programme, manually, before she went out; stopped it when she got back in (unless it ran out) and then FFWD/REV through the tape to find the wanted programme when it came to watching. No timer scheduled recordings of any type; no multiple channels; nothing. Now, she timer-records, properly, everything she wants to.