My 2p contribution is that after 350hrs I've decided that airspeed control is the most important single thing.
The airspeed on final doesn't matter much, so long as it is right at the start of the flare.
And the figure will depend on the aircraft configuration. The trouble is that a PPL is not (IME) told that it varies according to configuration (according to weight, basically, for a given flap setting).
If I come in even 5kt-10kt too fast, I always bounce about; the alternative is to do a perfect flare and settle into a ground effect glide taking me halfway down the runway
