I'm betting that stitched splice is probably 90% ~ 95% of the rope's tensile strength. The 5:1 WLL is 2000 lbs. but if you want stuff to last longer, 10:1 WLL is 1000 lbs. and a lot safer. That makes the 5 or 10 percent loss of strength from the splice pretty negligible, since we cut the recommended WLL in half.
So, I guess the question might be, would you really drop a 1000 lbs. chunk of wood onto that sling? I'm thinking the branch might break before the sling does, but if I was dropping 1000 lbs. wood I'd be using something a lot bigger than that sling, anyway. I'm just getting used to the sewn splices on my KM Max climbing line, and they seem just as safe as the hand spliced ones, but I admit that I was a little nervous at first. I think that's just human nature. It never bothers me to use sewn eye prussiks, maybe because they're in basket configuration, but still... something about that terminal eye that creeped me out, at first.
I bet the sling works fine, and that if something breaks, it won't be the sewn eye. I say that because I think if it wasn't true, ABR wouldn't have put it together in the first place. It's a good question, though, and I definately understand where you're coming from... it just doesn't look as strong as a hand spliced eye, but on some ropes they are just as strong. Hope that helps.
