Here's two M type ebauchons, long. Similar enough cuts, except one is Primo grade at best, which is to say it's pretty poor, and one is XX for real.
In both shots, the one on the right shows strong, even, tight grain, well oriented. It's clean, nearly flawless, should make a hella nice pipe. The left block is... practice grade? No grain, lotsa pits, a piss poor piece of wood for most purposes. And probably cost 10 times less than the nice block (a 30 dollar piece and a 3 dollar piece).
Looking at plateaus, an experienced cutter or maker can grade these just from the skin:
Rolling lumpy skin on the left, moving to super tight pins on the right. And the reveal is just what you'd expect... washy rolling grain vs tight, well oriented grain.
Front face, these are all cut decently, the X grade block on the left is a little crooked, but both XX blocks look really nice, the middle one very vertical in grain, the right having a nice fan outward, will make a nice brandy or a dublin maybe?
And again, these blocks range from about 15 bucks to about 35, and should produce pipes accordingly - probably a sandblast or rustic out of the X grade, and that XX and the XX "select" if you will should both produce stripey smooths.
All the mills grade slightly different, but Primo, X, and XX are your main choices, from low to high, and there's usually a sort of "ultra" grade around too, which honestly it's fun to have around sometimes, but you can get smashing pipes out of most XX briar, it's seldom really needed to have these super amazing 50 dollar blocks around.
