During type rating training in a 737 Classic simulator with only night visuals it is not possible to see the exact position of the pilots feet on the rudders unless you shine a torch there which is a bit weird of course. Anyway, I observed carefully the brake pressure read-outs on the instructor panel during one particular student's take off run and there was proof that he was inadvertently applying dabs of brake pedal pressure as the aircraft accelerated in a slight crosswind. He had his feet high on the pedals with his heels clear of the floor and had no idea that he was dragging the brakes until he was shown the read-out on the instructor panel.
It is only personal opinion which doesn't count for much, but I believe in the age old teaching that heels should be on the floor when taking off and landing. With RTO there is obviously no need to shift feet up in an abort and with landing it takes less than half a second to lift the heels off the floor to apply brakes. No contest.