Thanks Steve.
In fact I
am really proud. When I see it finished next to my Soul and Talon I really can't believe I did that...

It took a huge deal of patience and concentration. And at some steps I thought I had messed it up but luckily I had been cautious enough and everything was OK. Only my paranoia that made me think things were going wrong...
Concerning the bridle, I did it exactly as described here:
http://www.tweelijners.com/tom/tomskitesite-en/KBB5.htmlSo all the knots are exactly the same.
Except for the pigtails at the spine end of the inhaul, where I added an extra knot 1cm closer to the spine from the original ones to try to change the length of the inhaul as you suggested.
This morning I tried it and I didn't notice any apparent change whether the inhaul's larkshead was placed at the first or last pigtail... :-?
I also read the web site that you suggested to me about the design and construction of bridles. I read all about the "sweet spot".
So I checked where my tow point was falling when "projected" onto the sail. It was not in the centre of the outer panel. It is much closer to the leading edge.
So before touching anything I thought to myself: "where are the tow points in my Soul and Talon placed?", to compare...
I saw they have their tow points also much closer to the leading edge than to the centre of the outer sail panel...
In other words, they do not respect the "sweet point" theory and they are placed much more "open" (away from the spine). But they fly like angels!
So I'm now lost again.
However, I also thought the following (doing a lot of thinking lately as you can see

)
If weight is placed to help tricks that need rolls, then perhaps I had too much weight on the LeQuartz... I had 10grams whereas the Soul only has 6gr. From 6 to 10 we have +150% of weight.
So I made a 5gr weight and changed it in LeQuartz.
I went out to test it in the afternoon and guess what... no wind. Zero wind... argh!

So I'll have to wait until tomorrow to see whether that makes any difference...
Cheers.