I'd add this into the discussion: Some of my pedal choices have been driven by the shoes, first and foremost. I have a narrow heel and I've found it extremely difficult to find shoes that work for me. I briefly considered using clipless pedals on my mountain bike, but could not find a mtb shoe that fit in my foot. I stopped short of trying SIDI mtb shoes because they were just too spendy for my purposes. So, I stuck with platform BMX pedals for the mtb. For road, the only shoe that seems to work is SIDI. Again, they're spendy but for the amount I ride on the road, I could justify it. Plus, I benefit from a stiffer shoe on road rides, as I have experiences some numbness and hot foot issues.

So, you might want to figure out what shoes will work for you feet and go from there, as not all pedal systems work with every shoe.

FWIW, I use Look Keos on my road bike. There's a bit of a learning curve with them, but I do like them. The cost is palatable depending on which model you choose and I've been happy with their durability.