Fit---Even though these have a large lens, they are a medium fit goggle. The fit a smaller face than the Smith I/O X (which I also have).
Compatibility---They fit with Smith Vantage and Lazer helmets in addition to the Anon Helmets
Lenses---Mine came with the Blue Lagooon, which is better than any low light lense I have tried to date (most of my experience is with the Smith options). The Blue Cobalt lense is ridiculously dark and a true bluebird lense.
Anti-fog---I haven,t found a goggle that I cannot fog yet. These did fine on cold dry days, but I was able to get them to fog around the top edges on more humid, snowy days. On a side note I am a sweater.
Foam---The foam is not nearly as thick as the Smith options
Strap---the strap is a little short when using my medium sized helmet, forcing the face foam down almost uncomfortably. Having to run the goggle strap all the way out places the adjusters under the goggle strap retainer on my helmet, and keeps them from being properly secured. Additionally, it has no silicone beading, which makes the goggles difficult to keep in place when pulled from the face and placed on the helmet.
Lense changeability---it is the easiest I have found. Rather than pulling the lense off, if you squeeze the frame from top to bottom, the lense will pop right off easily. To get them back in place, all you have to do is be within a few inches and they pop right back on. One caveat is that you have to be careful when lifting your goggles off of your face and placing them on your helmet...you can easily pop the lens out and if you are not expecting it, you may drop the lens.
Case---Nice vented case and goggle back to protect them while in transit.
5 stars for design, but 4 stars for execution because of the strap.