severe loss of steeze will be obtained the second you step into hard boots
they are better in the BC tho... especially on longer (3-10days) trips where you will run into some real issues with soft boots...safer for kicking steps like killz said, and much better with crampons if you need em...
that said, if youre that into the longer stuff you should just learn to tele or get a sled.
modern snowboarding boots have come a long way, and the spark R&Ds are the shit. IMHO i'm not in the backcountry to be a hardcore tourer when i'm snowboarding.... im there to snowboard... that means jibbing, spinning, tweaking shit and playing around on my snowboard...hard boots suck for snowboarding