Nick, the reason it is a toss up for me is that yes the splice will hold longer but there is that big "if" whereas with the knot you can see it all right there and there is no "if" I love splices but to be honest, even after following instructions to a T there is always a TINY bit of doubt in my mind.
That's where I'm at, I'm confident in my abilities to follow instructions but like bonner1040, being able to see it would be peace of mind for me. In a spliced eye, I'd probably still want to run a zillion threads thru it with a carpet needle and then hold that together with some heat shrink. I think inspecting the knot on occasions will keep me happy . . .
Thanks bonner1040, so when treestuff.com offers "sewn eyes" in the HTP, that's not exactly a DIY procedure I guess - I guess I'll use the figure 8 then!
http://www.treestuff.com/store/catalog.asp?item=491
Interesting that Sterling Rope does not appear to provide any information regarding rope splicing anywhere on their web site...
Whipping and lock stitching is only there to hold the splice in place under low or no load like getting rolled around in a rope bag in the back of a truck. Check out the sewn eyes on the market Grizzly for example. When I first started splicing I started with rigging lines to field test my splice and figured if they held up to that they would be good to go for life support.
I do like the fact you can inspect a knot every time it is tied, dressed, and set but I look at the splice before and after use each day for signs of slipping and deformity.
Heres the thing... IF you follow the manufacturers directions on a splice, don't screw it up or cut corners, AND you are able to finish it, its good. If you cheat, do it wrong, don't use instructions its just like an incorrectly tied knot, it won't hold.
Science says that the splice will hold over the figure 8 every time and I agree. Truth is if you are involved in an incident that approaches the force necessary to break a rope with either termination you won't live to tell anyway.
For me I would trust the splice, its permanent. For you, if you are questioning it, maybe the knot since its easily inspect-able and doesn't carry any doubt.