Hi aron82e,
You are making an assumption that is actually incorrect. The difference between them has nothing to do with differences in their materials.
They both order the same materials from the same supplier (Latex International) and neither uses lower grades or “seconds”.
The only difference is that SleepEz (not sleep easy which is a different company completely) also supplies latex from Radium so that they can choose the latex that they believe is better quality and more consistent and provides better value to their customer on a batch by batch basis.
In some cases it could and in some cases it wouldn’t. If it was just surface issues it wouldn’t make any difference . If it was a defect in the manufacturing of the latex such as a mistake in the manufacturing process or larger internal voids then it would. this is one of the reasons it’s great to have a good quality and ethical supplier in between you and the latex manufacturer so they can screen out and reject any shipments that don’t meet their standards.
There are certainly some latex sources that use latex that could be “second” quality or has been rejected by another manufacturer because of potential quality issues. SleepEz isn’t one of them.
You would need to look elsewhere for the differences between them. Post #2 here would be a good starting point 
Phoenix