Hi, it is very similar to the SMP which I've used before without any drama, but not as robust and forgiving as the normal peco code 75 'finescale'. I took great care to lay it flat (ironically replacing some code 75 which had rested there for some time) on a well prepared surface but now has dips and rolls in it after intially being flat. I know its not the board as it is good hard wood which the code 75 sat on quite happily as flat and smooth as a snooker table!
It's a bit of a mystery and really ticking me off as the bullhead does look so much better!
Best wishes
Nige