Purchased these recently and they have helped me become much more comfortable in the pool. I am not a strong swimmer and have a frantic swimming style. The things to concentrate on to improve are breathing and stroke. Prior to using these goggles I wasn't comfortable with my face in the water - so was unable to focus on improvements.
The kayenne goggles are a comfortable fit, and do not become loose or leak water. In addition the field of vision is much greater than other goggles I've used, allowing you to see more while in the water. This makes me feel more comfortable and helps me to improve. The goggles have not steamed/fogged up at all (due to type of plastic used), and to be honest you hardly feel them on your face. Oh yes, adjusting these goggles couldn't be easier, with a little button which allows you to increase/decrease the band length. Literally, less than two minutes out of the pack and I was in the water.
Since buying them, I have been able to get more lengths done in the same time as previously by swimming in a much more controlled fashion. I think they are a fantastic product, and I would definitely buy them again.