Hank, I don't really know, but looking at their line up, what I see is that the 1000 series tractors are designed by price. They are simply inexpensive and have strayed from the traditional Cub quality & features.
The 2000 & 3000 series tractors seem to be very nice units. There is a 2000 series here at my office, along with an 12(?) year old model 1862. The 2000/3000 series machines seem to be built for quality the way the older Cubs were built.
Stepping up to the 5000/7000/8000 series machines and things get a bit odd. The 8000 series Cubs are nice machines, but they are simply Kioti DK 35, 40 & 45 tractors painted cream & yellow. There is no noticable difference in the 2 brands. The 7000 series Cubs are also nice machines, but they are Mitsubishi tractors, there is no other equivalent here in the US since Mitsu doesn't actively push their brand. I'm not sure who makes the 5000 series tractors, Cub may actually do thost themselves? They appear to be nice tractors, my dealer has a couple parked out front right now. Size is good, not too small not too big, and the design is very familiar to a Cub Cadet owner who is stepping up in size from a garden tractor.
I guess it seems to me that for Cub to really get serious about their machines, then they really need to focus on the 5000/7000/8000 series tractors. They need HST transmissions and they need to have features that the small estate owner (us folks with a few acres but don't really farm) want when we shop for tractors. Comfort, ergonomics and some proprietary design. John Deere & New Holland, to one degree or another have had other companies make many of their small tractors for many years, but they have their own designs and they are built to their specs. Cub is simply repainting someone else's design. If Cub were serious, they would "enhance" the features and performance, and they would have some propietary features and designs.
All that said, I think in the range of their better garden tractors, nobody has the price/performance that Cub Cadet has. I hope that the current owners of Cub don't degrade their quality.