On our test dive, we were impressed with ease of movement, the ability to interchange and the way the mask fit, different than others. The straps are in a very comfortable web design that seems to make the mask feel like it is barely sitting on your face. The straps are also attached to the metal ring around the mask, rather than the rubber skirt, like the other manufacturers. This seems to allow the positive pressure seal to do its job, rather than being under the stress of the straps and causing leaks in the strap connection locations. The Neptune mask fit best and most comfortable when the straps were lightly tightened. I had little to no problems with the one hour plus dive, other than learning the breathing techniques as to the communications. I dive inverted a lot in our recoveries and this mask was a dream, as far as balance, communication, and fit in that position.