Non veni pacem mittere, sed gladium.
My understanding is that the bushings must be replaced yearly. They are all brass/bronze bushings instead of bearings, and the road salt eats 'em pretty fast. The tracks apparently wear well.
I suspect you will breaka a u joint, differential, tranny or T-case before you break the tracks. This type of conversion is very hard on drivetrains.
It's a good idea for a ranch truck when you need to get feed to bogged down livestock due to snow. Or when you get tired of dragging the buck and decide to drive the pick-up to the deer instead of dragging the deer to the pick-up. They don't show the driver attaching a small snow plow to the front of the truck, but that would be a great use if you lived somewhere that made sense.
Like Dan said, these would let you get you deep into the back country, then you'd break a U joint and discover there was not phone reception.