Just my opinion on them, They are a joke a fall real short of a good a/t. If I was going to buy 37's from BFG it would be krawlers. They do well in mud and not bad in snow plus are a true 37". The km2 lacks everywhere.
The Irok I have never personally ran, But was co rider with them on a rig. You really cant compare a SS irok even radial to a mt/r. The swamper will win hands down off road in the deep snow and mud, Rock being the only place they would be comparable.
I can say they melt off quicker than any SS tire, But are a lot softer than a lot on the market. Unless you have the money or a DD commute of 5 miles round trip, Don't expect much. Plus balancing a irok that chunks off road can be a PITA.
If DD and rocks are in the cards, Go MT/R. They will do well in deep snow aired down, But there is always better. In the end you have to pick what you like, Its you're money man, Plus you have to look at them. Try them, Not like they wont wear off eventually lol or you can sell them.
I took a shot with them, Bitter/sweet taste about them, But will recommend them because my incident has not been reported in a long time.