The airbus rudder pedals are designed with a pad to rest your heels. So, when you put your feet on the rudder pedals and slide them down, they will rest on the bottom of the rudder pedal as opposed on the floor. I was told by airbus guys in Toulouse, that the reason for this is, that the Airbus should be flown with the feet resting on the rudder pedals only and not on the floor. But If you end up with some ex Boeing instructors they will be forcing you to fly with the feet on the floor, because that how a Boeing is supposed to be flown (I am not sure 100%, because I have not flown a Boeing, but that what a guy told me). But flying Airbus with the feet up is comfortable and especially during landing with contaminated rwy in a little bit of a crosswind you don't have to slide your feet up to start braking, which could make you loose directional control for a short period of time. Also, on an Airbus, if you make a mistake, and apply full brakes before landing (which I never heard about, that somebody would do it), the antiskid will kick in and teoretically you would not even blow the tires (if they are in a good shape), not that I would like to try it.
But during the take off, I was told to keep my feet on the floor in order not to kick out the max autobrake during rejected take off.
I am not saying, that the above mentioned way is the only way, but that it is the way I was thought and it seems to work for me.