Look for pictures of the knives taken apart. Look at the build of the individual pieces. The sum of the parts equals the overall product. This is the reason (cost not being a factor) that my main EDCs are Hinderer XM-18s and the current sole Spyderco I own is a Native 5 FRN. On the Native, the way the two handle halves fit actually INTO each other combined with a much larger pivot surface area than any of the knives previously mentioned in this thread make it a winner for me. It is also USA made which is a high priority for me. Delicas, Enduras, and the Centofante are all great knives, but the Native 5 is arguably better.
As far as the pivot strength goes, an FRN UKPK would be comparable to those previously mentioned. My GF has one and it is a fantastic piece, especially being USA made and only $45. Also the GIN-1 has been surprisingly good!