Stay away from this boot if you can't try it for few times. - La Sportiva G2 SM Mountaineering Boot - Men's

I chose G2 SM for my winter ascend to a peak 18600 F , where temperature can drop to -90F. before the final trip I tried it twice in a two hours hiking to the 8000F peak, both times gave me serious blisters on front and back of my heels which took me a month to be healed, I thought that was part of the breaking and it would be fine in the final attempt. unfortunately it was total disaster, seriously damaged my left foot Achilles tendon in addition to blisters in front of both feet.

G2 SM is a good looking and warm boot, but has not been made technically right, if you try it and look at it closely you will notice what I am referring to. my six month training and a lot of money I spent was waisted and final attempt ended to descending from 16000F.
I don't recommend this boot.