In a lot of conditions a 30 ft R62 will harvest as much as the 30ft R72. 36 ft will make the 72 use more of the combine's horsepower_capacity.I don't think we would buy another 30ft for our conditions, however if you farm in muddy or hilly areas then the extra money for the 72 is justified.Again in our conditions the 72 harvested around double the last l3 we owned that worked with a 72. One thing is that it is very hard to choke the R72 in hard going.john