twin jets clanking

[DEEPLOU]

I've tried Apollo Bios and Twin Jets. Neither gave me the fine control I'm used to having. Neither have the power and neither is terribly efficient. They both felt almost like not wearing fins at all, but then I get the same feeling when I'm not wearing fins at all and I think for the same reason. If you like them, stay with them, they aren't my bowl of cherries.

I think people get that feel "almost like not wearing fins at all" translates into no power or efficiency.
I have many sets of fins. Started w/ Cressi Frogs always got leg or foot cramps. the Twin jets no cramps,
If you watch the bottom flash by and not pay attention to resistance on your legs you will see the Twin Jets do propell you through the water quite efficiently.

PS: not many other fins have pocket large enough to fit size 13 rock boots