185cm, 84kg's
I've tried quite a few different types of blade stiffnesses in the pool. I've been judging how well I like the blades/fins by how tired I am at the other end of the pool and how quickly I got there. I'm not trying to dink around either. I'm trying to put some pace on it.
I first thought that speed was a result of stiff blades and strong legs, but w/ that combo I was wasted after 2 laps of dynamic(but then again, I'm 1600m above sea level

). Plus, my open water diving gave me little bottom time. I think it was at last year's keys kraze that I used aquiles' gara LD's for a day and noticed my bottom time was pretty significant and w/ quicker recoveries at the surface.
My conclusion is that I'm privvy to a blade that's light and snappy. The LD's are great, but Aquiles reclaimed them from me and Cressi no longer makes them. So, I modified my HF's and I like them better than the LD's now. Lynn, one of the members here, had been timing me on 2 lap dynamics in the pool and the results were quite intriguing. I have 2 sets of HF's, one modified and the other "as is". My modified HF's produced times about 5 seconds quicker and I was much less exhausted after each set.
What has happened is that my kicks have shortened in amplitude quite significantly. Almost in half. What I like so much about the mono is that you're using a lot more muscles, but you're using more muscles less intensely than the few you use when "standard flutter kicking." I'm learning to incorporate my hips and back into my kicks, which is taking a lot of stress out of my quads. It kinda looks like I'm twisting/wiggling a bit through the water. Anyhow, it's cut down my oxygen consumption significantly and I'm now able to match my mono dynamic distance w/ my flutter kick distance.
So... something's telling me I'm doing something right.

Now, I'm just afraid to try something else when I've optimized my current gear.
Sorry for the long post.
Anderson