There probably is a difference in tensile strength and abrasion resistance when comparing the two materials (1600 vs. 440 Denier nylon). Will this translate into a "tougher" BCD? I don't know. I'm sure that a BCD made from either material will last a very long time, so long as the item is properly maintained and stored.
Double bladder wings are designed to serve as a redundant buoyancy control system. It is thought that if one bladder is punctured, the other bladder can then be used. Unfortunately, most bladders are punctured due to pinch-flats and it's possible that both bladders could be punctured by the same event. Arguably, a better way to set up a redundant buoyancy system is to dive with both a BCD and a drysuit. You'll have to decide for yourself which configuration makes more sense. IMHO, I think a single 22mm thick bladder is more than sufficient for a BCD bladder. If this is covered by an abrasion-resistant cordura-like material, that should be good enough. For standard open water recreational diving I don't think double bladder wings are necessary. In fact, some might argue that they are never a wise choice.
Hope this info helps...