I agree, and I think I’ve already seen indications of that in recent rides, since realizing that I’d gotten slack and lost good form.
For me, I’ve done the Elements of Style vid that Heretic mentions, and I do think it helps. Maybe I need to do it once or twice a week till my form is better, but I’m not sure I connect very well with the way it’s explained and I find it a bit more complicated to think in terms of 4 quadrants of the pedal stroke. (At least I THINK I remember it being illustrated that way?) I can do it during that workout, and I understand it ok, but I guess it’s hard for me to apply when I go out and ride.
So I already knew long ago before SYSTM became a part of my experience that spinning round circles as opposed to just mashing on the downstroke of each leg is a better way to go, and I had worked on my stroke such that I thought it was fairly balanced… Long ago… 
But more recently, I’ve struggled with loss of power over time, recognizing that age is becoming a bigger factor (and not liking that reality), and also fighting with some very long-term nagging hamstring pain on my left leg that just seemed to never get fully recovered. I’d have some short term improvements and think maybe at last it’s finally better, but the pain would always come back within a few rides, and especially so when I tried putting out very hard efforts, be they AC, or MAP, or NM types of efforts.
When a light finally turned on in my head that I was hardly using the hamstrings in my stroke, it made enough sense that I started looking for answers. (Probably still am considering such things as minor seat height changes I’ve made, but that’s another issue.)
What I’ve been doing for probably a few weeks now is focusing on the upstroke more consciously, not so much the round circles per se. I find it easier to maintain this focus on climbs, of which there are plenty everywhere I ride here in the mountains of Virginia.
And what seems easiest to stay conscious of and to monitor is to think of driving the knees up to the top of the stroke, feeling that nicely powered peak as my knees come up toward the chest on every stroke. For me, that just clicks mentally, but doesn’t require quite the mental focus that a 4-part stroke conception does.
I stay more conscious of that simpler concept and I think I’m quicker to recognize when I’m losing that and getting lazy, just pushing down with the quads I’ve grown too proud of! 
I do occasionally remember the helpful tip about “scraping your shoe off on the bottom of the stroke” but it’s not something I find as useful or needed.
I’ve seen a small increase in my power numbers, nothing radical, nothing I would wager much on, other than to say that I now KNOW my stroke has improved and I need to sustain that improvement and let the hamstrings get stronger to match the quads again.
They do let me know that I’m asking for more from them than they are accustomed to giving, and for longer periods of time.