I have Speardicver 90 with Omer foot pockets and I have Moanas….medium I believe, with Pathos foot pockets.
For our diving here, I prefer the stiffness of the Moanas. My SD 90s are a bit soft for my taste but I would guess Dan's stiff blades would be more like the Moanas.
The Omer foot pocket is softer and overall, to me anyway, a bit more comfortable. I do get a little blister on my heel if I don't us thick socks though.
The Pathos pockets are a bit tight on the top of my foot. But with they thinner tendons, JD, the maker of the Moanas, said they're the best pocket for his blades so I went with his recommendation.
The top of my toes got blisters at first. But my son and I heated them in almost boiling water and stretched them a bit while hot on our feet (with socks on)
You can definitely see a right and left fin with mine now based on foot shape. But, as Dan told me, they will try and revert back to their original shape if left in the sun. We keep them shaded and they're held the shape for months now.
I think it's just a lot of personal choice. If I'm shallow reef hunting and being sneaky, I like the SDs. If I'm moving in current and doing deeper dives, I can get up and down faster with the Moanas. But again, I haven't tried the stiffer SDs.
Hope this helps.