I learnt to fly in a Harrier GR5!
I was developing the simulator at the time (late 80s). I spent many night shifts teaching myself with a bit of help from a pilot colleague. After a few weeks I could fly a fairly stable approach with only 1 in 10 landings resulting in a fireball.
I don't suppose the CAA would accept those odds, but I was impressed. It had a practical purpose as I had to test the bombing system by flyng sorties over the North Sea, destroying any ships I came across (mostly fishing boats and ferrys, but you never know where the enemy could be hiding
).
When I moved 'on' to a real C-152 (also a single engine plane) several years later, I immediately felt at home in the cramped cockpit, recognised most of the instruments and knew what to expect from the primary effects of controls. It was a bit tardy though. And I still haven't found the thrust vectoring lever.
When I progressed to a 4 seater Archer, I found the extra 20 Knots in the circuit a bit of a handful at first. You have to think ahead a bit quicker to get everthing done. I am not sure if this would be an impediment to initial training. On the one hand, you are busy enough in the early days so more speed would make things worse. On the other hand, if it's all new anyway, there is nothing to compare it to and you would just learn to do it.
TallGuy.
p.s. I learnt to fly IFR the same way, this time in an MD82 simulator that was finished except for the visual system so all flying was done looking at a white sheet.