look at the edges of the core.  i.d.k. if it's one of those dunlop products that use a filler i've heard about, or if all extra firm layers are going to be like that to a certain extent.  or is that not even what you guys are talking about, when you refer to crumbling?  either way, i don't want any latex that looks like the bottom one.  what started making me nervous was one company in particular i noticed warning over & over how their warranty does not cover biodegration (& you must keep the layer encased of course).  and that's their showcase photo (from a different company)- doesn't make me want one too much. 

not that being rough around the corners would even be a factor while sleeping on it, i just don't like it.  so do the firmest talalay layers do that as well?  is anything from l.i., even their 44ild, going to be like that?