Tom, CRs:
I distinctly recall reading a few years ago that most pro racers did not pull back at the bottom of the stroke, but simply had reduced pedal pressure on the final portion of the pedal circle, ie from 5 o'clock thru 9 o'clock (viewed from the right side of the bike).
Nonetheless, I think that a major benefit of pedal restraining (besides the "in bike" feeling you mentioned) is the stability of foot placement and safety on bumpy pavement.
Another factor is the development of good position and pedaling technique. My own experience taught me the advantage of toe clips & straps:
I had learned a 'bad habit' of pointing my toes down a lot, to help claw the pedal around the circle. I learned this from first riding "beach cruiser" bikes with plain rubber platform pedals. Having the toes down seemed to keep my foot more stable on the pedal.
I carried this 'toes down' technique over to my first road bikes, with significant disadvantage: The 'toes down' style raised the heel, which then 'lengthened' the leg, which necessitated raising the seat, which then required buying a new (larger, too big) frameset.
I changed from a 63 cm frameset down to a 60 cm (c-t) after I learned to ride a flatter-foot pedaling style. I've continued to ride a 60 cm to this day.
Jacques Anquetil was the only person that I recall that rode the toes-down style successfully.... and I'm definitely not "Maitre Jacques!".
Andrew Gillis
Long Beach, CA