Just my opinion but I would look for a 715 diesel. We ran one for years and it was a great little combine. We had very few problems that were not normal wear items. The reason I say to look for a 715 is that they offer a few bonuses over the 615. The combines are essentially the same except that the 715 offers a larger grain tank, a few more horsepower, and the ability to use a 4 row corn head, whereas with he 615 you are limited to a 2 or 3 row wide head. If corn is not really a concern for you then that shouldn't be a worry for you. The only other thing is that these machines are getting up there in age so parts are getting hard to come by, so make sure you know of a good salvage yard for those "No Longer Serviced" items from Mother Case. Hope this helps you some.