I ran my own experiment last salmon season. I rigged up several sets of identical plugs, K14s and K15s, with both Gamakatsu siwash hooks and the Gamakatsu 510s. Both setup included a split ring attatched to the screw eye of the plug and a #50 barrel swivel connecting the hook to split ring. Results were that once hooked I landed more fish using the 510s. Several fish lost on the siwash hooks were due to hooks breaking at the eye and straighting of the hooks. Lost one fish on the 510 due to the swivel breaking and another due to the split ring opening up. My conclusion is that the 510s are much stronger overall but may not be worth the cost unless you are going for large fish. We landed three over #40 last season.