I,m not German but Dutch and speak German reasonably well (English isn,t my first language either so you might got a double lost in translation bonus

).
Do you have a link, because all inept reviews I found was a 2019 test between the first Duotone and first Slingshot (and i,m very curious myself

).Edit found and look in to it.First vid:
The Unit5.0:
very light wing with a very light build. This is a bonus in the handling, but makes it also more fragile for contact with concrete or the wingtips.Great handeling especially when neutral on a wave due the flat profile.The grips are very comfy but a vague due the foam. placement is spot on although the front handle rather small for big hands.Due the very soft and comfy grips AND flatter profile it need a bit more wind (the 5m Unit needs as much wind as asome other 4.5 or 4!, but in the perfect wind it has a very light and comfortable soft feel. In light wind it needs a sensible hand to get it going.Due the less lower end it isnt an typically freeride wing like the Echo, but the Handling is superb, light and playfull.
Ensis 5.2:
Superb construction almost without wrinkles but with reinforcents there where needed. on the tube. When starting it feels powerfull and adjusts from itself to 45degree above wich really helps with low wind and when starting on small boards.The very wide grips need some time to get used too, but the FEEL of the wing is very stiff and direct and the wide grips feel very intuitive and easier to grip as the smaller ones and has all the bonusses of a grip without the downtrades they found with some other wings.
Like with the Echo boom you can slide your hand over it when tacking..Like the Duotone Echo it gets really going quick and when going it is very well balanced with a very balanced profile. Because the wing is rather flat (Medium aspect ratio) it goes really well upwind without getting jerky and when depowering there is almost no leach flutter. When riding waves it drops quicker and that is where like the Unit or Slingshot V2 easier stays level without dropping. Overall you need to adapt with the Ensis a bit by pulling it earlier up. Due the stiffer profile the Slingshot V2, the Airrush and the Unit have a lighter more playfull handeling on a wave but the Ensis feels the most sharp, precise from all of them at a slight expense of the handeling. Fitting exact between the freeride Echo and wave Unit. When jibing and tacking the Ensis feels more playfull as the Unit because in that part the more precise handling helps better as the Unit its softness.
What they found very positive was that the wing automaticly goes to 45 degree and has a very stiff precise feel in a very wide windrrange. Excellent low end and still very good in high wind without flapping around
Duotone Echo6.0:2th gen completely new designed. with the 6m the coil leash is too short to flip it with more reinforcements on crucial positions.The profile is very clean, the boom is a one size fits all but gives a bump in the 6m tube as it is bigger as the 4m wings.The frontgrip is wide enough for big hands and got a neoprene cover to prevent scrubbing you knuckles
When grabbing the wing by the front strap it is controllable but it has a tendency to flip on its back quicker as other wings due its very stiff profile and when that does the too short leash doesn't really help (this isn't a problem with the smaller sizes).The low end planing is very very good but when pumping the 6m is less effective as the smaller sizes.For freeride it is just the best in its class on all courses. In Handling: when the wingtips drops a bit the fronthand can stay in position and you can control the wing by the back hand. Fotr it size this feels very balaced due the boom instead of the grips although this is a matter of taste. Windsurfers will find it very intiutive but also non windsurfers get very quick used to it.
When riding waves the handeling on the fron tube is okay and good enough but when the speed or windspeed drops it has quicker as most others the tendecy to start swinging left and right and up and down. When you grab the BOOM at the front this problem is solved and you will have a better handeling.Compared to the tubed wings you need to grab the boom far in the front in manoeuvres and for tacking you need a slightly wider radius because the wing tends to dive forward a bit. That said the windrange is very big. An 80kg rider with a bigger board and 2000 foil can fly from 12 knots till a decent 20knots.Bonus: the window is very well postioned, but need some carefull folding, dur the boom it is the biggest package.Verdict: it is a LOT better as the first one, there are wings with a more playfull handeling but with the boom it feels very intuitive for windsurfers and it has an excellent windrange. Who really wants to ride waves and progress in it will find its handeling a bit slower and less playfull as some other models like the Slingwing and Unit.
I will later look at the airrush.