I have used this implement a little bit now, and am starting to get a feel for what it will do and be useful for doing. I've never seen another one, but in case somebody else finds one they can at least have another frame of reference for things.
I thought this implement was relatively light, at first. It is not. I put on the back of the 186D, and this is at the limit of what the machine will do. Accurately, it is too heavy, but if careful, it is doable. The 3 point relief valve squeals if opened rapidly. I was surprised the 186 wouldn't lift it easily, to be honest. It will lift my tube-frame 5 1/2 foot disk harrow that weighs, I guesstimate, about 600 lbs, without squealing. Fortunately, the implement usually rolls, so the tractor doesn't need to carry or lift the weight much.
The power requirements are minimal. My 186 has always felt a bit underpowered, but is sufficiently strong to power the cultivator under all conditions I have found. The cutting heads take minimal power, even when chewing through weeds in very hard packed soil. (Hard enough that a full size pickup doesn't leave tire tracks of any kind)
The cutting depth seems optimal at about 1 inch below grade. Much deeper and the cutting heads hurl clumps all over the place, and carve a trench two feet widen isn't really useful. Shallower, and uneven contours in the soil mean not all the weeds are scraped out.
The implement works very well on clumped weeds, and on weeds which have branched, shallow roots. It is ineffective on Bermuda grass, discouragingly, since that is a primary invasive species I want to control. Other grasses are poorly handled, too.
I have discovered where it excels: restoring untended baseball or softball diamonds. It is a marvel in the clay/brick dust mixture. It makes other field renovators look like pitiful toys. Pigweed and even Bermuda grasses in clumps ARE uprooted in the hard pack, and it leaves exactly the right consistency of material behind to finish drag for a sharp, professional appearance.
Otherwise, everything works as intended. The auto retract system is surprisingly gentle, though I wouldn't use it on trees less than several years old, mostly for the bark toughness to build up. The back and forth shuttling tosses the tractor around a little bit, but is not rough, so long as the implement is lowered fully. It is really a drawbar type implement with the ability to lift with the three point. Trying to run the implement when not fully lowered really batters the mechanism and tractor.
I'm still not sure if I can get what I want from it, but it is really cool to watch in action. I'm probably going to try replacing the cutting teeth with small cultivator sweeps to see if it will slice grass sufficiently to be useful.