Do not forget that first batch of SAM 440 Ep is a 10 layer motherboard...
A 10 layered motherboard it will be almost unbreakable... SAM 440Ep Flex it will be just a 6 layers only Motherboard...
The Number of layers is irrelevant. More layers does not mean better or stronger (FR4 is more ridged that Cu). The main difference is it easier to route (ie. quicker to design) and a bit more expensive to have 10 vs 6 layers. 10 layers does not mean that it is thicker. The fibre glass layers are 'normally' made thinner when more layers are used.
