The last big walnut we cut from a yard was over 4 feet in diameter and it fought us all the way. At the mill we found a 5/8 eye bolt that the band saw cut right through. Needed a new blade right after that cut but the old one was resharpenable. Anyway real nice wood, very fancy. The limbs were up to 2 feet in diameter. We cut them into boards (be carefull it takes forever to stablize) Bottom line lots of great wood, but there are many problems you encounter.
bill