My wife and both have Apollo Bio-fins.
My wife could not use the Apollo springs because
they don't make them for the extra small sized fins.
She also had problems with handle/loop of the original
bio-fin strap rubbing against her Achilles tendon and giving her a blister when she wore low booties.
I purchased a set of Innovative EZ springs
(the same ones in your link) for each of our fins.
We have used them for over 100 dives in a year an a half
with no issues.
We love them. So easy to don/doff with the strap/puller.
(To me the Apollo straps SUCK!, the handles face the wrong direction and can cause blisters)
My wifes feet are so small that I had to cut the EZ springs down
to make them even smaller than the smallest size.
While it can be done, it is really tough to do. The hardest
part is bending up the spring to form the new loop.
The heal rubber of the EZ springs now comes in colors.
EZ Springs Colors
If I had to buy them again, I would definitely get the yellow
heals, as it would be a nice identifier.
Innovative also makes the same style as the Mantas,
(called EZ springs "PRO") for just a few dollars more than the
clip version.
Something to think about when selecting the "Manta"/"Pro" style.
That style mounts by sliding a plate over the mushroom, similar
to the clip version. Tension holds
the plate against the mushroom when the fins are on your feet,
same as clip version.
When the fins are not on your feet there is no tension. Normally
there is enough friction to hold the plate on the mushroom,
however after some use the plate cuts into the mushroom slightly
and the friction is reduced. This can cause the fin to be lost
if you are shore diving in surf and holding the fins in your hands
or have them attached to a fin strap during entry/exit.
The plate can work its way off the mushroom and leave you
hanging onto a strap with no fin.
You can keep this from happening by using a stainless safety wire
or a zip tie and wrapping it around the clip & mushroom.
(If you search SB you will find posts of people that have lost
fins)
The Manta web site even shows you how to use an oring as
a keeper.
Manta Safety Keeper
The Clip versions don't have this issue because when the strap
is inserted in the clip, the strap part of the clip pushes up against mushroom holding/trapping
it so it can't slip off like in the Manta/Pro version.
The only slight bummer was that the clip on the EZ springs isn't the
same as the one from Apollo, so you can't just swap between the
straps. You have to swap out the entire clip that slips over
the mushroom. But, since I've put these on, I've never
been back to original straps/clips.
Hope that helps.
--- bill