This boot is pretty much guaranteed to keep you feet warm in pretty much any conditions. You can use this boot for hiking, mountaineering, ice climbing, anything where it is cold. Removable liner is nice for using at camp or just to take out of the boot and dry quicker.
Rather heavy and when ice climbing, it is hard to get a feel for where you feet are.
Nothing will be this warm and it really depends on what you want to do with them.