A few years back I looked at them very serously. The type of work I was doing, I needed a very small dozer (one I could load on my skid steer trailer) . (Every one has a big dozer and I wanted to get into a line of work that it was not feezable for larger dozeers or jobs that were too small for them to fool with. The Nortrac (also sold under a dozen different other names) seemed practical. It was around $12,000. and it would be new with a warranty and I really liked the 3 point hitch. And I felt I wouldnt be getting someones else old worn out dozer. Education does not come cheap and I learned almost the hard way. I was really hot on this dozer idea. I found a dealer that had 4 of them sittilng on his back lot and he made me a price I almost couldnt refuse. When I really got him pinned down about the reliabilty and who would do the warranty work and thats when things fell apart. He said he was being suied for every one he sold and they had alot of trouble. I still wasnt satisfied. I found and talked to three or four different people who owned one. They had alot of track problems, they had problems with the blades brakeing, they had problems with the transmission. Finally I saw the writing on the wall. So my next choice in the same price range, and smallest was a JD 350 a Case 350 which are no longer made. The used Mits. and Komatsu were just appearing at that time and they were getting top dollar. I have had three small dozers in the past ten years. The first thing I learned was if it is painted yellow, you had better have a pocket full of the green when you needed parts or repairs. My first dozer was a Massey Furgerson 200D with a perkins diesel and a little ripper on the rear. I had to do quite a bit of work to it to get it in tip top shape. They no longer make it and parts were very hard to come by. I used it for a few years and someone came along and offered me a hansome profit on what I paid for it and what I had in it. I though a little Case 350 would do what I wanted to do, so I found one with very low hours. Parts were available for it and I had it for a few years. I didnt like the steering system in it. It just has a brake band which locks up one track when you want to turn and not a true clutch disengagement. I sold it and made a little money. I then ran across a 1965 (old enough to vote) Allis chalmers HD4. A church had owned it for many years and it was kept inside and was in very good shape. I feel that Allis chalmers was way ahead in compareing it with the other dozers. Yes I know they have not made them for years. But I have been able to find any part Ive needed so far. I love the leg room compared to other dozers. You have the radiator that sits right under the dash, and the fan can be reversed in winter and warm air wil blow on you. They are very easy to work on compared to the other dozers. It is small enough I can haul it on my skid steer trailer. I use it quite alot. All of these dozers will beat you to death if you are on them all day and your arms will feel like they are about to fall off. So at my age I might start looking around for one of the new small Komatsu or the Mitbushi. One of thease dozers might be your best bet if you want something that small. But I would stay away from the Chinese dozer, (thats where the Nortrac is made) also sold under the name of Rino and a few other names.