I bought these in rock bottom as a returned product. Lets start from the bottom -
The sole is Vibram - a brand which speaks for itself. It is quite stiff, hence the B1 rating, but I have seen it rated as B1/B2, B1.5 and B2. The truth is it is a good stiff sole, with a noticeable flex at the toe. Either side of the bend though it is quite solid - good for balancing on the arch or kicking in with the toe. In terms of crampon compatibility it has a lip at the back (not sure why the picture shows a new classic style crampon?) so it can take grivel new-matic clips at the back. I have the boots in size 47, which dont fit the G10, G12 or air-tech, but do fit Black Diamond crampons without the need for an extension. I'm looking at the BD Seracs for these.
The standard insole is quite hard, but not uncomfortable. I have medium to wide feet, and this boot was very comfortable around the foot. The laces don't however pull through the eyes particularly smoothly, so a progressive lace up is needed.
The boots are also very light, and in a UK climate very warm. I'm yet to use them in the snow but I'll update when I do. From reading elsewhere it might be a case of wearing nice thick socks!