Hi, I bought a Blue Seventy PZ3TX this spring. I was doing IMTX and thought I'll take any advantage to get me through a non-wetsuit swim.

Mind you, I was HIGHLY skeptical that these little piece's of fabric could actually be beneficial, provide speed, flotation, etc and I was more or less buying into some expensive marketing BS (yes, I am that sucker). Anyhow, I get the thing and decide to give it a pre-race test at masters in the pool the week before IMTX.

First thing I noticed, when showering pre-swim, was that it did not seem to absorb the water. In fact, the water was sheeting off. Weird but cool. When swimming the workout, I was more or less killing my lane mates. Much to my shock and surprise, I was swimming about 5-6 seconds faster per hundred without really trying! Holy schnikes, I could not believe the difference it made.

So in my experience, they DO work, but it's not flotation, it more of less making you more slippery through the water.

PS. Like you, I am mostly a full-wetsuit swimmer, living in Idaho, where we swim in snowmelt reservoirs and such.