Lots of people seem to like Klim, I've never tried them. I use my snowboard boots-made by Roxy. They are warm (more than most I've tried), and have lots of support. I like the stiff feel, some people might not. I'm not sure about the slight forward angle it puts your calves at, I don't have a problem with it. Some people like straighter boots. Plus there are lots of womens snowboard boots available at a much lower cost than sledding gear.
They have held up great, especially with kicking the boards constantly and beating them up. I've worn them for 2 years and they will last at least that much longer. The bottoms are barely worn at all. I have an ankle that gives me problems after tearing a ligament. In snowboard boots I don't have to worry about moving it wrong or hurting it. They don't give me the chance to hurt it.