I commented once, but here is some more:
I run 18# Mason line. Like most leadcore, it is a different color every 30 feet. I run it on an Okuma level wind line counter reel (the only reel I own that isn't a spinning reel) and matched Okuma rod. It's wound over several hundred feet of 20-pound Stren braided backer. I have never had all 100 yards of lead out yet.
I calculate about 5 feet of depth for every color (30 feet) of line I let out. In actual use, I have found that the first two colors run shallower than that, and at 4 colors (120 feet) out, I can feel -or get hung up on
- humps 20 feet down, but when they show on the graph, a quick reel-up to 100 on the line counter keeps me from fouling. Sometimes I just lift the rod in the air, and I am getting confident with that, but I don't have silver-lined pockets so most often I reel up quick and scared-like!
Leadcore will run higher in the water column at a faster running speed. Alternatively, creeping at 1 mph or under, and/or turning has found the bottom for me in 60 feet of water when I thought I was only 40' down. Part of the reason is that it takes a little while for the leadcore to settle down to its equilibrium running depth at a given speed, and if you are running slow, sometimes a breeze or making a turn is like stopping relative to the water, and there you go.
All in all, leadcore has worked well for me. I am still developing my own sense of using it well, but it has helped my fishing a lot. I run mostly 6 or 8 pound flouro or mono leaders on everything, and didn't have any break-offs this year. How? By paying attention to drag, and using sensitive but shock-absorbing rods. My lost fish were mostly idiot factor losses, while a few were just plain heart-breaking. You might need stronger leaders in big water, but here in Vermont 20# fish are not common.
I spent a lot more on fishing than usual this past summer, but I only lost a few lures this year, even though my hours fishing more than quadrupled. I have lost hundreds of dollars in past years, so I just keep telling myself that I really only spent a little more than usual with all the savings from not having to replace a lot of dependable go-to lures.
My leadcore outfit was pricey by my standards, but in reality it ran me under $100 all together- worth it for sure.