Thank you very much for that fascinating and informative review Abgd.
You refer to the short cycle life of LiPo cells. It fascinates me that if you ask almost any so-called 'engineer' in the electric car business "how long does the battery last?" they immediately start telling you about the capacity. You have to say "no, how many cycles does it last" to get to the real operating cost. And very few of them will answer the question head on.
Even then, a characteristic not picked up on by commentators is that capacity doesn't just fall off a cliff after x cycles (though it might) ; it degrades progressively, every time you cycle the battery. This means that a car that could just about do x to y last week might not make the same trip next month quite so easily, and probably won't do it all next year. Inconvenient for a car driver stuck on the hard shoulder of the M6 and a bit of a concern for a pilot of an electric aircraft.
My experience with models leads me to completely endorse what Abgd says about multiple motors and designs being completely different from traditional aircraft. The motors (and batteries) scale so well that I don't see why you would stop at 2 or 3 motors: 10 or 20 might offer almost as much efficiency while protecting you from the great danger of controller failure, as has been pointed out.
Motors and batteries are best combined in compact pods, reducing heavy and wasteful cable runs to an absolute minimum. That's what a model aircraft is, and one of the main reasons that they work so well. Multiple pod mounted motor/battery combinations might aid maintenance and also be designed to burn off the wing without destroying the aircraft when the inevitable Lipo battery fireball develops. (Petrol seems really safe after exposure to a burning LiPo cell!).
All this is well within the reach of amateur developers and we can expect to see numerous examples of the multi motor aircraft appear in the years to come (except in over-regulated UK, of which Wherner Von Braun once said "The history of spaceflight might have followed a different course if amateur rocketry had not been made illegal (in the 1920's) in that inventive country").
Will full-size electric aircraft ever surpass petrol ones? The secret to all of these new technologies is economy of scale and scale has become quite significant in the model aircraft sector, enough to attract serious Chinese manufacturers. Todays 'ready to fly' model, straight out of the box, not only outperforms it's IC engined counterpart of 20 years ago but comes at an FOB China price of maybe 10% of the traditional model in real terms. Nothing like that can ever occur for conventional IC engined light aircraft.
So a future electric lightplane might be vastly economic in comparisom with it's traditional counterpart, especially as low utilisation (compared with a car) would favour the limited cycle life of the batteries. None of that makes up for lack of energy density compared with petrol, but the 4/5 Hours safe cruising endurance of our petrol powered spamcans probably doesn't fit in with the future shape of hobby aviation either. So on the whole, I'm a believer.
If you have been, thanks for reading!