I can't completely agree or disagree with you either as I'm not technically minded at all when it comes to machinery, we can agree that today's 500cc machines are too powerful though.
Not so sure about the size of the rider though, Mikkel Andersen was bigger than his dad! Take your point though... I know I've seen the last 2 SGP3 meetings, last years was the best speedway racing olIb think I've ever seen anywhere, and the performance of the bikes was a lot closer to those of the 70's & 80's where they appeared to be operating at max performance for the size of the track, you get the feeling that today's machines would be more suited to the long tracks.