R70 had a twin turboed Deutz where the R60 was NA. 
We had a P3 R60, it was a nice machine, like other said, keep it clean, lots of power but the engine just sips fuel. Takes awhile to get some heat in the cab, but it will cook a turkey at 0 degrees outside. 

They are a fine machine, we have a long shoe R62 now and there are some upgrades, but I wouldnt be afraid of a well taken care of R60 or 70. The only thing on the P3 machines is the manure spreader chain on the discharge, wasnt a problem but every once it a while a cob would get under the chain and throw it off.