The point at which the lenses meet on the ION 3/Europa 3 is a bit different than most similar designs (we've had masks in the line previously similar to the one mentioned). The "joint" produced quite a gap - similar to what you see looking through the corner of a fish tank. This latest generation offers a virtually seamless view. It is a smaller skirt all around, not just in width.
Doug-
Doesn't the side windows distort the viewing field? Seems like once in the water, it would create a different viewing plane even if the joint were seamless. I agree with Hank that this could be distracting.