Usually takes me around 3-20 tries to pass a hard map, depending on the number of ninja notes and rhythm changes. Haven't been bothered to grind any insanes yet though. I'm at the stage where I'm grinding for full combos on hards that don't have many streams xD
Jumping from normal to hard, after grinding on one hard song, I found the rest possible instead of impossible, because I learnt how to right click.
Jumping from never played to easy was hard though, I D'ed the tutorial the first time.
My pp's at 3200~ ish right now basically due to grinding bad apple on hard.