What happened to the others? What model and usage factored into the problems? Facts to determine actual problems are needed. Did they lack in maintenance or were they abused in some way? I would not jump on the design until we know the facts behind why they failed. Mechanical man made things that are used have a tendency to break. I am not disappointed in mine. I believe if anything Mattracks are over engineering this product to make it ....
The other two that I know were both groomer-useage. One has already been described by T2T.... the other is a set of Mattracks that were the heaviest duty set that they manufacture for tractors. They were wildly expensive and any tractor application (baring pull-off contests), would most likely require dragging something very heavy around...with potentially high drag from friction (ie, tiling earth, etc.). So, a drag weighing 450 lbs or let's say 800 lbs only has so much actual force given that it's sliding on snow...so 450 lbs turns into some small amount such as what T2T described as being able to pull it around lightly. So, then add in friction when the thing is dragging through snow...so there's more weight on top... let's say it's 800 lbs... 800 lbs of vertical force over relatively well-groomed trail could turn into ... 200 lbs of horizontal force when sliding over snow...then over bumpy snow add some additional friction, etc...
My point is that if I drop a set of Mattracks on a Suzui samurai lightweight mini-SUV and also put that set onto a F250 then the difference in natural weight/wear due to one light and one heavy vehicle is greater than pulling a drag over snow... also they have different units for just that...heavy vehicles but still F250 to samurai falls into a common class of theirs....
But, all that stuff aside...for the cash that these things are... the amount of cash you could buy a LMC1200 for... you shoudl be able to pull a drag over snow. To the point of being able to take these things and drive on pavement... taking corners, etc.. on pavement should put quite a bit of stress on them so it still is surprisng that a drag could shred these things. It makes me think that they ARE NOT over engineered to a very significant degree...
But there is also a big difference between the failure of metal structure, wheels/rollers/spring, and rubber belts.... so belts should first go if regularly/consistently overloaded by pulling something heavy...but it should be an extreme situation when metal failure occurs.
Anyway, lots of unknowns but for the money??? It seems they should last a heck of a lot longer w/o major structural failure. Just a cent or maybe 1.5 cents.