That is why they make so many kinds of fins.
I have the Rondines and love them. Just as comfortable in a flutter kick as my TwinJet split fins, just as effective with a frog kick as my SuperRockets, and I find them very effective with the backward kick. They give enough to never cause cramps and they spring back with good propulsion after a hard kick.
They are not my only set of fins because:
The SuperRockets have better propulsion against a very strong stroke, so I wear them with doubles; and the SuperRockets are easier to control in tight areas, so they are my cave fins.
The TwinJets are light and compact to pack, so they are great for air travel, and I bought them in Medium, so they are perfect for me with a wetsuit bootie but do not fit well over the rock boots of my drysuit.
I don't care what happens to my Dacor Turbo-Flex, so they are my pool fins!
theskull