I have a pair of Quattro, and I have other fins before like Beuchat Contact Pro and others. IMO the material they have used for the plastic strap including the quick release is not optimum, comparing to the other fins I owned before.
For my case, it didn't break, just when you pull the strap to fit your feet the plastic strap is too soft. For my other fins, the pull was more crispy.
Then when you want to losen it (readjust not quick release), you need to push the button very hard in order to release the strap, like you need to do it with 2 hands and need to push the button really hard and pull back the strap. This is the worse thing about the strap design IMO.
Finally, the quick release, when I pull the quick release, I could feel that the plastic material made up for the quick release is relatively light, you know, not the expensive type of plastic.
I haven't switched the strap to spring strap yet, so I cannot compare, but my estimation is, it would make every issue I mentioned above better, this is just my estimation. Em, my other fins do not have these kinds of issues. I think the reason is, Mares has allowed cheaper material for the fins to cut cost, in my opinion, even more expansive plastic is not that expensive. So, it's a bad trade off.
Other than that, as you know, the Quattro did get very high rating, and this is the reason why I brought one.
However if you are looking for something easy to kick with, this is not one of the fins that would do it. You may need to adjust. Comparing to the Beuchat fins I owned before.
If I were you I will try the Jet fins, if you think that it's too stiff, try the split fins, bio fins, tusa xpert, atomic aqua, whatever split fins. Or even the Tusa Imprex Tri-Ex fins.