I have four sets of fins, of three types.
I have ScubaPro Jet fins (two pairs). One pair lives in Mexico and goes cave diving with me. The other lives in Seattle and has been my mainstay fins. Jets are heavy (which is nice for dry suit divers, and people diving doubles). They are thick and stiff, and make precise positioning easy. Unfortunately, the foot pockets in Jets are peculiar -- a foot pocket than fits my feet in my dry suit gives me a very small blade, and therefore less power. I have to kick a lot more often than my buddies, which causes fatigue.
My other set of cold water (and cool water cave) fins is a set of the Dive Rite paddle fins. They are plastic, and light, which is a downside. But they have more than two inches more paddle than the Jets that fit the same footgear do, so I have a lot more power. I have problems with the back kick in them -- I think more experience will sort it out.
I have a set of Deep See Pulse fins for pool work with students. They are plastic, and light, which is why I use them there. I tried using them for a warm water trip, and hated how flexible they were -- I lost a lot of the energy of the kick into fin flexion. But they are inexpensive, and great in the pool.
I owned a set of ScubaPro TwinJets. They went away. I had to use a set several years later, because I had nothing that would fit a new dry suit's footgear, and I was vividly reminded of why the earlier set had gone away.
