I believe I’ve seen all of the videos GCN has put out on flat/platform pedals vs. clipless. For the uninitiated, “clipless” refers to a lack of toe clips and straps… you still, ironically, clip into clipless pedals.
What they rarely cover in the whole discussion is foot position, though they did for a second or two in the imbedded clip.
First, clipping into clipless pedals, to spoil the clip and add my two cents, is only slightly more efficient than using platform pedals with little screw-in flat spikes and mountain specific shoes without cleats, until you get out of the saddle and sprint. At that point, a person who has used clipless pedals will feel vastly safer to hit the gas harder because their feet are connected and secured to the pedals.
Having ridden a 30-mile loop with the Elite A-Group on Tuesday night on a set of platform pedals (though, admittedly, the pedals I used were the cheap, stock plastic platforms without spikes). At a decent pace and cadence, it’s simply too hard to keep your feet in what I approximated was the proper position.
And that word, “approximated”, was the important part of that sentence, folks. You have to guess… and at 90-rpm, guessing where your feet should be gets old in a hurry. Especially bad is when you’re a little off and you can’t move your foot in little increments while moving at that rate of speed. What I ended up experiencing was a lot of pain from having my feet in the wrong place on the pedals to work the crank efficiently for my ankle, knee and hip joints. For that reason, I’ve never bothered with trying platforms again. Perhaps cycling at a less aggressive pace wouldn’t prove so difficult.
Next is the mountain bike issue (and this applies to potholes on the road as well – especially bunny-hopping an unexpected pothole). When descending, you can experience everything from roots to rocks making the descent tricky. If your feet are clipped in, you don’t have to worry about your feet bouncing off the pedals. The spiked platforms wouldn’t be as bad as straight up plastic, but I’ve always felt better being connected to the bike in clipless pedals.
In the end, the choice to go clipless or platform will come down to choice. This commentary is included to help those new to the choice to make a reasoned choice. It’s always an interesting topic.
UPDATE: Be sure to check out the comments. What a great topic for well-reasoned discussion based on experience. Great stuff.
Fit Recovery 
Whenever I use platform pedals, I spend most of the time looking down making sure my foot is planted in the right spot. Clipped in just slam your foot down and go.
Exactly.
I’ve heard MTB riders claim that flats are better as you develop better foot placement v cleats and if you train yourself properly they’re more secure and allow for position adjustment when needed. However, I’m not mad enough to indulge in tearing down mountains and probably breaking my neck 🤣
🤣🤣🤣 Love it.
I have always loved the pedal debate. My two cents: I always clip in for road riding/training rides because as you said, with that kind of cadence and fixed position, it’s just nicer on the joints and for generating power. I’ve ridden clipless on my mountain bike too, and yes, way better for not getting bounced off (though I can’t say that really happens very often, no matter how chunky the trail), but actually worse for honing your jump and bunny-hopping technique because you tend to pull up on pedals instead of doing a proper foot scoop. And if you’re doing jumps and tricks, flat pedals win by a large margin (no-footers just wouldn’t happen if you’re clipped in).
The main reason I stopped clipping in on mountain bikes is because if I got to a technical feature I needed to get off to look at, and then had to clip back in to ride down, and I couldn’t get my one foot clipped in fast enough…it has meant a few terrifying descents with only one foot clipped in.
So interesting! That makes a lot of sense and I’d definitely cede to your extensive expertise on mountain biking. Super cool. 👍