That does sound very interesting. When you say much less stretch than mono I assume you mean nylon. By comparison to the normal 25%/30% of nylon what sort of stretch would you say the Advance has - at a guess ? If braid is 0 - 2% and 'normal' nylon 25%/30% would you say the advance is in the middle at about 15% or even less %
Why would it need a leader ? Because you'd opt for a thin mainline ?
I consider nylon with 25% a very stretchy line, probably the stretchiest of lines practical for coarse use.
I would hazard a guess Sufix Advanced is less than 15%, more like 10%. Difficult to compare as although the Sufix does stretch, it doesn't tend to start stretching until nearer it's breaking point compared to a normal nylon mono, making it appear even less stretchy under low load. At least, that's what I've noticed with it on the lure.
Because the Sufix has low stretch, there are a few things you can do to get best benefit out the line:
• you can fish it lighter at distance without the bite indication being numbed down.
• thinner line means further distance - much further.
• thinner line also cuts through surface tension easier, so it settles quicker.
The downside of fishing light mainline is you'll need a shock leader. You could tie a 5yrds of thicker Sufix Advace on the end, but because of its lack of stretch, it also lack shock absorption necessary on the cast: I guess you'd need 12lb leader to achieve the same shock absorbing qualities as an 8lb maxima leader- so you might as well use cheaper maxima as it's thinner and probably handle the abuse better in the long run (?).
As I said, you won't see any benefit from a medium chuck, and you might as well spool up with 5 or 6lb maxima straight through - but if you're going for a long chuck for bream, there are definitely benefits to be had from using a mainline like Sufix Advance.