I've been working on my swimming form, trying to improve my dolphin kick so that when I post some swim videos I don't get self conscious ;^) This feels like the most "balanced" version of the Lunocet to date, as I'm able to sprint or cruise steadily, accelerate or swim smooth and slow. It's uncanny how well it functions in several different swimming modes! My streamlining is improving too, and last night's swim was faster and smoother than any before. No problems with the fin either-the pins stay put, the spring does not get slack/slop, it just plain works well. It's also significantly lighter than the 2014 pro, and feels like it in the water (or in my dive bag!)