I had a similar experience and made a few tweaks that made the kite work much better for me, although many love it stock.
I will have to measure and post, which I'll do later tonight. I've been wondering what sorts of tweaks others have been trying out as well.
In the end, I really like the kite now. As you noticed, the JL takes a bit more tending it him due to the large sail size - it just takes longer to rotate and flip!
The low wind range is quite good - the large sail really works there.
color combo Mario!
I had the same observations and experience with my full size 6th. I found it's low-wind range to be exceptional. The ONLY modification I did was to tweak the bridle settings. The kite does some very nice slow JLs but does take a little more tending.