Got a pair of the fire-iridium goggles and have used them just a few times to date. The goggle looks pretty slick with a grippy elastic strap. The clarity of the lense is really clear, probably the best lenses I have ever had in a goggle. They are very breathable with plenty of ventilation. The fire-iridum lense is really only suitable for a sunny days and I found it a little difficult to make out the terrain when things got cloudy. One other issue was the general shape of the goggle. It fit my face perfectly but I felt like I had blinders on sometimes as the goggle extends so far out from my face, you feel like you can't see as well to your feet or to the sides. This can be a little disconcerting in the trees or on a slope full of people.
I ended up cracking the lense but Oakley replaced that free of charge.