Scottwrote a review of La Sportiva Karakorum Mountaineering Boot - Men's on January 13, 2011
This boot performs best if doing a lot of hiking in the alpine and working in the outdoors, doing long backpacking trips or like trans-alpine hiking/scrambling trips. I use this boot 5+ days of the week as a guide on a glacier in New Zealand, and it gets a lot of abuse. I've given the boot 4 stars because despite the abuse it receives, it has stood up well. Other guides I work with have found the boot lasts about 9 months to one year with 4+ days a week wearing it.
The features I appreciate on the boot are its rugged and thick sole (which absorbs a LOT of shock), high rand (which is longer on the inside of the boot to protect against feet rubbing together), lace locks, softer materials around the ankle flex-point, and high, padded tongue. The aspects of the boot that could be improved are its low, too-soft of materials behind the heel, excessive number of lace-loops going down the toe, and the amount of stitching and construction on the tongue (more panelling= more places to wear out and allow water in!).
I think the manufacturer's description is very misleading for three reasons:
(1) It is not insulated enough for climbing in winter or at higher altitudes,
(2) the sole becomes as flexible as a hiking boot after a few weeks of use and is therefore inappropriate for prolonged front-pointing, ice climbing, or use with a crampon that doesn't have flexible linking bars, and
(3) It is not waterproof, and you should not expect it to be waterproof after one or two stream crossings. However, this isn't necessarily a bad thing. Waterproof boot linings are a nuisance in very wet conditions, since they tend to keep water inside the boot as well as taking a long time to dry out.
And, if you buy the boots, replace the laces immediately. La Sportiva laces may be abrasion resistant but are notorious for their inability to hold a knot!