Thanks for the comments, it would seem the 25 mt is good to practice with but I am interested by kevspilly's comments. What effect does having a twist in the line have? I have a fury in the bag but have been practicing with a HQ Breeze as the winds have been light recently. I take it the fury would have the same effect as a twist due to its yo yo line but again I am interested as to how this helps to stops fouling of lines. Again thanks for the comments.
For me, the yoyo line on the Fury (0.85) makes tip wraps more frequent and much more difficult to remove. It seems too easy to have the leader line pulling to one side of the sail and the yoyo line to the other. Without a yoyo line, then I can usually fly out of the situation.
Regarding twists in the line helping avoid tip wraps - twists usually don't make things worse. For example, if there is a tipwrap, the leader lines (almost?) always pull the same way across the sail. And for rollups where it is important that the lines don't fall too far down the leading edges, they can help a lot as a they keep the lines close to the centre of the kite.