They are very unique and break up the profile of your mask lens as well as stop the glare on sunny days. They can be custom ordered and made to your design.
A few friends as well as myself puchased a pair of them. They are ok for hyper or concept ball, but they distort vision (looks like a screen door). They are totally useless in rec ball, it is difficult to see and a real pain to clean off.
Personally i would spend a few extra bucks and get a mirrored thermal lens, they are much better for tourneys. If your looking for something for rec, invest in goggleflage, they really break up your mask and help to blend.
This stuff does break up the goggle shine/silohette that gives you away in the brush/foliage. It also cuts down on glare, and is not very difficult to apply. They also have some outrageous patterns available if you want to stand out more. You do get used to the "screen door" effect if you leave them on for five or ten minutes. You can get your team name or sponsor on them.
Makes cleaning after a "gogg" shot a little harder. They do cut down on visability some, especially on overcast day, dark woods, or rainy days. They also catch snow and allow it to kinda stick and build up some, not a problem for most players I'm sure. The louder styles will make you stand out in brush, rather than blend in.
I'd say they were worth the asking price. I don't think there is anything out there quite like them. I would not put them on my primary goggles unless you play somewhere that has sun 90%% of the time. I would reccommend them, and people get quite a kick out of them when they see them!