Woods makes three versions of their brush bull cutters, the heavy duty 5' BB6000x weighs a little over 1300 lbs, the 5' BB600X weighs 1,000lbs., and the 5' BB60X weighs 600lbs. Quite a difference between metal content between the 6000 model and the 60.
I'm sure other top manufacturers have same size cutters with different duty levels of construction. Landpride has their smooth top heavier version like the Woods Brushbull which is model RCF2060, it has the 2" cutting capacity.
Woods even has their lighter, and less expensive, duty Heritage line.
Maybe you should consider the Woods BB600 or BB6000 or the Landpride RCF series for their heavier duty construction, cutting capacity and durability you are after?
Having said all that I have a Woods BB72X and it works for my use.