I snowboard hard boot, soft boot and also ski so can give some advice.
I use K2 enemy (fairly soft) at 173 and Line Mothership at 170 and 180. I like the enemy. Yes it chatters a bit but is very forgivign on bumps, jumps and trees. Its pretty narrow. The 170 Lines are fatter and softer but a bit too small for me. I spent most of my time last year on the 180s. They are stiff enough and long enough for me and are quite fat (97 mm).
I am 5'8, ~150 lb. In the past, I have tried Salomon Pocket Rocket, Volkl Explosives and Atomic R:Ex.
If I were buying something this year, I would get the new K2 public enemy (cheap, durable, pretty good, 1 cm fatter than my enemy) or the Karhu Jak team edition (fat twin).