Srb, would Z plugs really have better contact area in all cases? Thinking about it, I guess it really depends on the speaker post barrel, right? If the barrel is sized perfectly to match up with the Z plug, when the plug flexes to the nominal size (upon insertion), one would get the theoretical "perfect" fit. But because there's so much variability in different binding posts (from different manufacturers) we end up with variable fit and variable contact between plug and post. I suppose that's why we see so many different styles of banana plugs, including locking bananas. Like anything else there's pros and cons. Those Furez look like a really nice solution, combining a "soft" copper tube with a resilient dielectric center pin to provide a flexible and adaptive fit. Pretty clever!