Hi thecountofzero,
Thanks for taking the time to share your thoughts and feedback in such great detail … I appreciate it :).
Mountaintop’s testing appears to indicate that there is little difference between them in terms of durability (normally 100% natural Dunlop is more durable than a blend or synthetic) so I’m keeping an open mind about this even though my “instincts” say that the 100% natural will likely have an edge. Time will tell. It is also a denser and more resilient material (you can tell some of the differences from the synthetic needing two firm bottom layers and Skyjumper’s comments here about how using the 100% natural made a difference in the underlying support) but they are both good quality materials relative to other types of foam.
If cost wasn’t a factor and I could comfortably afford it I would personally choose the 100% natural but of course each person may have a different personal value equation and cost may play a more significant role for some people than for others but if your testing doesn’t indicate a significant difference between them then any added benefits of the 100% natural may not be as important or worthwhile for you.
Phoenix