If you have stainless or titanium liners, that's OK, you have a nice gripping surface along with the mechanical properties of the metal liner. But if you're depending on the mechanical properties of the Zytel, count me out. :barf:
Molded nylon, even filled nylon, parts age and fail in very strange, unpredictable ways, often at far lower loads than you would expect. I have a lightweight Spydie Matriarch in my collection that I would hate to bet my life on, with its no-liner Zytel handle. The single-liner G-10 Civilian, on the the other hand, is a dandy piece of lightweight equipment.
G-10 is just so much better than Zytel in load bearing applications that it's well-worth the extra $. By the way, G10 doesn't actually cost very much, although it's probably harder to machine in quality applications.