Probably more important than what you get is how stiff they are. I've used: Escalpez greens, Omer Milleniums, Gary Fisher powerblades, C4 flaps and C4 falcon 30s. Here are my (extremely subjective and personal) opinions:
The omers were too stiff for me and didn't give much return for my efforts. I suspect that this was because if I kicked hard enough to bend them enough, I was wasting too much energy. If I didn't kick enough, I just didn't go anywhere.
The Escalpez were/are good. Subjectively they didn't have much grunt or power transfer, but they served well. I may have to do a more subjective test sometime, like Dave's Taupo effort.
The powerblades (long fibreglass, soft-medium for those that don't know) were good, though too long for some situations. Mine had a manufacturing fault, so they're on the floor right now, cracked through where they meet the footpocket. Getting replaced shortly.
C4 flaps are soft almost to the point of stupidity. These are the only ones I haven't tried in the ocean, so I can only comment so much on them. Very efficient, but you've probably guessed I favour soft fins.
Falcon 30s are what I'm borrowing at the moment and are the pick of the litter as far as I'm concerned. They handle current better than any of the others and for me are probably just right in terms of stiffness. Depth feels comfortable and turning is a lot easier than in the Fishers.
If i was only swimming in the pool or freediving with little or no current, I'd take the flaps. For general use, falcon 30s are the pick and for price, the escalpez greens are great value. Gary's fins lose to the carbons, but they're still good. Milleniums can suck a tailpipe.
Me: 6', 78kg, good fitness. My brother (5'9", 90kg, strong but not fit) liked the milleniums.