In Reply to: horsepower comparison posted by GregW on February 20, 2019 at 21:36:57:
In addition to all the good advice already given, a compact diesel will likely have a hydrostatic transmission which is part of the reason a smaller, lower horsepower tractor can perform like a larger tractor. One thing a smaller compact diesel will not do as well as your 640 is use ground engaging implements like disk or a two bottom plow. Keeping your 640 for those tasks is a good plan. I transitioned from using my 43 horse 860 with a rear snowblower to a 30 horse Kubota with a front snowblower. The Kubota is faster to clear my yard than the 860 was.