The last few seasons have seen many manufacturers create a backcountry specific snowboard boot, and the Aspect is K2's answer to this growing sector.
The boot itself is well constructed, and looks old-school mean - matt black, with dull metal robust lace loops. Yet under the old-school look is a high-tech boot, which will get you where you want to be.
Starting at the bottom is the Vibram sole, with its traditional chunky lug design. There has been a good lot of thought put into the design of this, from both K2 and Vibram; not just with the excellent grip (which, let's face it, is vital when scaling an exposed ridge line), but also the semi-automatic crampon compatibility, which makes donning your spikes super easy.
The inners have 'Intuition Space Heater Tec': basically a reflective heat blanket inset. It seems to work well, although my feet rarely get cold in any boot. I really didn't like the ankle-cutouts on the inners though; I guess these are designed to give your ankles room to move - but I found that when new, they really chafed around, rather than on, the ankle.
The inner is tightened with simplistic velcro sides and strap, and fine tuned with the K2 Conda Boa system. This allows for a loose fit while skinning, but is easily cranked up for the descents.
The outer sits a little wider than the sole, but with such a good sole, you won't notice this when hiking, and they sit snug within the Spark RnD Magneto bindings I was using on test.
The lace system is fine, and I particularly liked the way I could lock off the first 'foot' section of the laces with the funky little locking eyelets, ahead of tightening up the remainder.
The rear of the top of the boot has a flexible neoprene section, which is great for skinning, but does lend the boot to feel a little loose around the upper shin/calf when riding. However this isn't noticeable when on foot, or leaning forward on a steep bootpack. To compensate, K2 have added a power strap - but rather than going around the whole top of the boot, it simply tightens the front, leaving the calf able to stretch out the flexible section.
To summarise: The K2 Aspect is a kick arse mountaineering boot, that many splitboarders or backcountry snowboarders wish they could of had years ago. It rides well, and can offer up a stiff lock through to a loose surfy feel, all with a quick spin of the Boa. It does take a little breaking in, but then most boots do, and it's rather heavy. But like a yapping puppy, it will soon become your long term friend.