The perfect fluorocarbon leader for walleye is as invisible as possible underwater and has a 10-12lb test. When lure fishing, you will want to use a somewhat stiffer leader material. When fishing with smaller live baits, your leader should instead be softer and have a little stretch to it.
When fishing with jerkbaits for muskie, using a stiff wire leader is always a good idea, as stiff wire provides security against bite-offs and improves lure presentation. When casting with bucktail spinners or trolling with crankbaits, you can instead use a heavy fluorocarbon leader.
Modern fluorocarbon leader materials have become really durable and are made of high quality, which means that more and more anglers use and trust them when fishing for pike.