I bought my 15-22 for one reason. Competing in action steel and tactical matches. Both of which require a lot of movement, some call it run and gun. Target rich environment scenarios that will include standing, prone and kneeling across a 100 yard playing field. Did I mention a lot of running?
So, to answer your question. Yes,both.
Sort of.
Except in competition most folks tend to shoot from the position at which they are the most competent/accurate....we should work on all positions to improve our skils.