I use leadcore, mainly the Kryston Score stuff, in about 3' to 4' lengths that i splice myself. I've found it to be pukka so far - very heavy yet nice n supple too. I use running rigs 99% of the time, with just a buffer-bead pushed over the swivel spliced to the leadcore, and an inline lead running free on the leadcore. I then tie the leader onto the mainline with a palomar knot through a small spliced loop. This way, if i do snap off, the lead is guaranteed to slide free, and as my hooklink is 50% or so less of the breaking strain of my leadcore, it'll snap first anyway if a fish does get snagged.