Let's risk bringing down the wrath and sanction of many of the forum by suggesting that:
1) If you have to fly in very low winds, the Akuji is probably not the best kite for lightest winds.
2) I would vote for the Prism QPro SUL - Seriously good for straight lines, and can trick quite well for a SUL as well - and I'm keeping this view until someone lets me have a go with a Ghost, Fearless SUL etc.
The disadvantage of the QPro SUL is that you may have to order one from the USA.
3) Maybe this is too old school and for lighter winds than you were thinking of - but how about a Benson Inner Space? - yes I know it oversteers, but with patience can squeeze quite straight corners our of it. And it's British.
- Or in a similar oldish school vein, perhaps a Skyburner Prodancer? - probably again a transatlantic order.
Yan has a lovely German (as in posted from Germany) UL - which seems to fly down to within a mph of the QPro SUL, and is very pitchy. - Leave him to say more about it.
Talon UL is nice, but with all those weight refinements, don't think goes quite as low as some others. i.e. it was trying it that made us realise we needed SULs.
Suppose there are the Robertshaw Fury ULs and SULs - which definately trick and have straight tracking, and are relatively light for their size as well. But just not convinced about their performance in low winds. - We owned a 0.85 UL long before we bought our SULs, and watching a team struggle with full size Fury SULs in ~2mph at a festival demo convinced us that we had made the right decision in investing in QPro SULs for ballet work.
The Nirvana SE WW has the most amazing video set in Venice about it. - From the video it looks more floaty and tricky that a QPro SUL. It is on my wish list to try - but haven't seen it over here.
Do you still have the Ozone? - For comparison, we find the Ozone flies lower than the QPro SUL, but not quite as low as the Inner Space, and the Ozone's straight flying qualities fall between those two kites.
My gut feeling is that the WW may fly as low as the Ozone, and give you straight tracking.
Why don't you order a WW from France, and then let me try it?