I guess we need to define “better”. Some people prioritize protection, others prefer a minimalistic design (think OB Defender vs Peel). Neither is “better” per se, but only in regards to how they meet someone’s particular needs. From my perspective, a case that is as minimalistic as the Peel but as protective as the Defender would be the “best” case. Of course, given the limits of our current technology, this is impossible. So the question then is, “Given current technology, which case provides the greatest amount of protection with the least amount of bulk?” To me, the “better cases” are those that most successfully balance these conflicting attributes.
The “better” cases seem to have both stiffness and shock absorption. Using the Sheath and Synthesis as an example, the edges on both are made from the same material, so they’re roughly equal in shock absorption, but because the Synthesis has the addition of a rigid back plate, Caudabe claims it is more protective, which I believe (it is torsionally much more rigid than the Sheath, which easily twists). So, by using the combination of two materials, they were able to make the Synthesis lighter, just slightly slimmer, yet also more protective than the Sheath.