I just don't like hard boot riding. Everything fun is well, harder. Jumps, pillow lines, chutes, I find to be a much bigger pita in hard boots. Biggest advantage is often they can be lighter and you can effectively kick steps in hard snow. Which is really a big deal. You lose that surfy feel, and if you like to tweak jumps, that sort of thing, forget it.
Sb.com has it's hard boot fans, but most of the gang on there are soft boot riders. Hikeforturns, rode in hard boots for a bit and went back to softies. For some applications, there is no doubt that hard boots are a better choice. For 99% of what you'll do, it probably doesn't matter.
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
Snowolf: awesome boots for mountaineering and ice/mixed climbing..... doable to use on a snowboard, but far from perfect. they would be good for the skinning/touring, but i wouldn't want to be dropping cliffs or hitting 30+ft kickers in boots like that. not enough leverage as the calf doesnt go high enough, and they don't have the critical ankle support and cushioning that a snowboard boot has.
the reason snowboard boots somewhat suck for hiking in is because they are really good for snowboarding in. you can look to other types of boots to make some of the hiking and backcountry living aspects work better, but IMHO it's always going to be at a significant sacrifice to the performance of a modern snowboard boot - for snowboarding in.
i guess it kind of depends on your individual motivation for being in the BC, and whether or not the kind of riding you want to do can take that sacrifice for a gain in touring ability/long term comfort.
they would for sure.... hard boots will have less play in them, although a climbing boot like snowolf put up has maybe too much articulation in the ankle for doing some things on a snowboard safely.
one other thing that can help when traversing with a split is to wear the "skis" so that the snowboard's sidecut is on the inside edge of your foot, not the outside. try both ways and see which feels better for you.