i have made at least 2 thousand dives in open heel fins and i find spring straps to be the most uncomfortable strap i have ever tried. The line of contact is just one thin line so the force per square inch is significantly greater than with any stock strap; plus they are more negatively buoyant than stock straps it would seem.
some springs have a pad that spreads the load over a larger surface area.
My booties have a groove at the base of the heel for the spring in any case.
they are the most comfortable fin you have ever worn, but nobody has the same shape foot or same comfort zones as anybody else.
tha apollo foot pocket is the softest and most pliable i have seen.
if you are doing the same flutter with splits that you are doing with paddles, you are doing the wrong flutter with one &/or the other. The proper flutter for a split is not the proper flutter for a paddle.
It may be "kicking" that silts, finning with fins is a much better solution. I think it is very likely, from my watching thousands of tourist divers each year for almost a decade, that for the typically untrained diver, the split fin just might stir up more sand/silt than a paddle.
Trim / body position along with proper finning is what keeps a diver from silting. When i fin my long blade free dive fins (gara2000's) in any style (flutter, scissor, frog, modified frog, even dolphin) my trim dictates how far from the bottom the turbulence is, so any finning style can be done with the fins at any distance from the bottom.
frog "fin" frog "kick". I think everybody here understands. All things being equal with respect to "trim" and "fin" (meaning as in how you move your leg like as in "kick", not the piece of equipment, "fin" which is on your foot. I think we cleared that up.