Last summer a friend gave me a beater which I tried on my commute, it had no cleats or straps. I found my foot firing off the pedal and into the front wheel at the top of the stroke I had no idea I was using that much of the top of the stroke. Luckily there are no big climbs on my commute because I know I really use the upstroke when I am out of the saddle and when I spin at high cadence. In fact when I am up out of the saddle and climbing in a higher cadence I have to make sure I don't bunny hop the bike up the hill.

When my pedal stroke is using the whole circle the riding is easier & less effort - unfortunately I still don't do it all the time without having to think about it. You don't have to ride like an animal to get a lot of value out of these and IMHO their proper use is a valuable skill and they are a tool you should learn how to use.