Well, you pretty much decided against all brands so I don't know what to do to help you.

But, WHY? Carbon? soles?

I know they are stiff, but I hate to tell you this - tho you should know already. sometimes you walk with your mountain bike - due to really bad conditions, wet, muddy, etc; or because it is Just TOOO Technical? Maybe you are too good to get off for technical but mud will get everyone!

I think because you do get off and walk, that is why they do not make carbon soled mountain bike shoes. Also, it might be hard to make the lugs that are on mountain bike shoes for traction in carbon? Just a guess?

I've worn Sidi for both mountain and road for years and years. I love them.

spoke