After splicing a few eye to eye prusik cords with Bee Line and Ultra Tech I have arrived at the conclusion that it is better to buy them with sewn eyes, for two reasons. First, the eye can be sewn with the cover on, which definitely reduces wear and tear on the core strands. Second, by sewing the eye you reduce the amount of bulk and stiffness in the body of the prusik where the bury of the Brummel Splice is located. So, unless you have a bunch of bulk Ultra-Tech or Bee Line laying around that you have to use up by hand splicing, I would not waste my time. Buy the sewn cords. Any of you other experienced splicers want to venture an opinion?