Originally Posted by
Caliper
If I had to pick just one pedal and shoe it would be three bolt road cleats and shoes since I rarely unclip on gravel rides anyways.
That's what I was thinking when I first put my gravel bike together in 2017, especially since the regional gravel riding doesn't tend to get muddy. On the very first gravel ride with SPD-SL, I spent the last 20 miles unable to properly clip my left foot in, riding with my cleat vaguely floating on top of the pedal. Very unpleasant.
While I slightly prefer the feel of SPD-SL mechanism over SPD, I don't think there's any tangible performance difference. If there's any question, I always err in the direction of SPD.