I got this board a couples of weeks in the 151. I bought it strictly for park but was definitely surprised at how well it held together bombing down a few runs. It's soft but maybe not a 3 as Burton rates it. My Hero is softer and that's rated a 4. My Graft is softer too. The board is fast and light and it's a breeze to spin. I didn't have any problems on landing kickers and it held together nice even on really sketchy landings. My only complaint is that I don't think it has that much pop which makes getting up on rails a little trickier. Maybe I should've gone with the 55. Either way it's a good board and holds an edge nice but I'll mostly use it for park rails and booters.
burton doesnt even have a flex scale, they have a "feel" scale which is different.
Lib Tech Skate banana
Burton [ak] 2l Cyclic Jacket
Holden Northfield 3L pants