Over the past 10 years, I have dove, tested prototypes and broken all kinds of different fins. From plastic, to fiberglass to carbon, every fin has its advantages and disadvantages, but you can only wear one pair at a time, therefore the right pair can either burden your dive day or completely enhance it.
Now there are a lot of brands of fins in our sport and I have completely lost touch with plastic fins and what manufactures are doing with them now. However, due to the nature of plastic fins, in freediving, it comes down to the foot pocket. Therefore, if plastic is what is in your budget at this time, then make sure the foot pocket fits extremely well and supports the fin. To understand the importance of the foot pocket being able to support the weight of the fin, you should consider going into a dive shop, like the Freedive Shop, and having them explain how this works. It is a little to difficult to explain in writing. From what I have seen in recent years with the plastic fin though, is that Rob Allen, Ocean Hunter and Mares have actually taken some time to produce a good foot pocket that is designed specifically for the blade. Ocean Hunter as well offers their plastic fin with a removable pocket.
The next progression in performance, reduced weight and options is the Fiberglass (commonly known as the Composite Blade) fin. For a very long time, a majority of all CenCal and NorCal divers swore by fiberglass fins. They are super strong, have good flexing characteristics, can take an absolute beating when shore diving and the performance is really good. The fiberglass has excellent snap (the speed in which the blade returns to straight) and is soft enough that in comparison to plastic, reduces fatigue in the legs . . . . significantly. Good brands to consider for Fiberglass are: Dive R // Penetrator Fins // Leaderfins // BlackTech
The next progression in performance, feel, massive reduction in weight and customization are Carbon Fins. Talk to any diver and ask them if they will ever go back once they have gone Carbon . . . and the answer is "NO". There is no greater asset to a single breath dive, than the fin. Good Carbon will help you reduce the number of kicks and energy it takes to descend, but great Carbon, fit to your height and weight, will not only do the prior, it will give you power and speed with less energy. Over the years, I have dove the Dive R Carbons, C4 Carbons, BlackTech Carbons, Penetrator Carbons, Moana Carbons, Carbino GFT, 2 different Prototype Carbons and the Meister Evo Carbons.
For the past 2 years, I have exclusively been diving the Meister Evo Carbons and prior that I was diving the Dive R Carbons. Meister is a Greek company and extremely well known throughout the world and especially Europe as a top fin producer and wet suit designer. One of the reasons they have had such a small footprint in the US is because of their ability to handle the demand. They make fins in small batches under extremely tight tolerances. It is a gorgeous carbon blade this is the lightest of the blades mentioned above, yet due to the manufacturing process and carbon weave, is exceptionally strong. During the 2017 Nationals, I actually cracked one of Greg Fonts' fins because a big swell knocked me over and my weight belt, and my ass, sat right down on it (but seriously, who lounges on a boat in 6 foot swell with his feet up on the seat!!!). He then dove with the cracked fin for the next 2 weeks and during Nationals without issue. 2 weeks after Nationals, he was in Louisiana chasing Tuna and while he was sitting on the swim step of a boat, his fin got swallowed into the prop wash and got chopped a dozen times. And yes, he continued to dive the fins without issue for the remaining of that trip. LOL, classic Greg Fonts moments!!!
The Meister EVO Carbon is sold and distributed by the Freedive Shop and can be installed in either the Pathos or Stingray foot pocket.
For me personally, I want a fin that does a couple specific things really well:
Is very soft in the bottom 1/4 of the fin so I can change my course and make balance adjustments with just my ankles or the smallest of movements.
Will not buckle when I crank on them to start making my way to the surface or loose their structural integrity under power.
Low profile side rails. Bigger rails are put on fins to make up for cheap Carbon and a lack of structural stability. Good Carbon will funnel more than enough water over the tip of the blade to produce all the power needed.
Performs really well when surface kicking long distances.
Designed to fit the best footpockets.
Can be customized for my height and weight
Has a good warranty and support
If you are thinking about Carbon, you need to check these out and of course, they are supported by the amazing customer service and warranty of the Freedive Shop.

I currently use the Meister EVO as well. I as many thought no F-ing way carbon would be worth the cost over my plastic fins. Then thankfully I won a bet with my brother and he had to buy me some carbon fins making them totally affordable to try. I went with the Meisters after doing a lot of research and ultimately talking with Greg at the Freedive Shop. Initial experience was instantly verifying they were worth it. I dive the north coast and suddenly found myself covering twice as much ground looking for Ling holes with the same effort. Flash forward a few years to now, once I got over treating them like "my precious" I hauled them on shore and kayak dives like any other piece of equipment. They've got a lot more scratches on them but no structural damage whatsoever. I highly recommend these. They do come in a range of stiffness's so do talk to the folks at the Freedive Shop for recommendations.
Have you tried the new Cetma Edges? I hear there are the new trendy blade with an interesting foot pocket concept (no side rails). I did a TON of research and almost pulled the trigger on a pair. Another question, I understand how Soft/Medium/Hard play into how much you weigh and what kind of current you primarily dive in, but could you explain the height aspect? What tweaks or changes are needed for a tall vs short guy? I'm 6'3" 190lbs for reference. I use the Carbon Subcrafts in a combo medium to medium soft at tip and absolutely love them. I've also beat the snot out of them and they haven't broke yet! I've dove strong current in them and still they do me well.