Oh my god... people read this thread and don't listen. RAR MY 3TPA AND CRIME SCIENCE IS GOING TO OWN... as if heavies always run 1 tpa and minimal crime, especially late age.
75% DR numbers don't count. They are not stable as soon as you gain or lose land, and it's a pain to get up to 70% DR let alone 75% without being hit. Besides, whatever DR you run, you can assume heavies can and will run the same, all else being equal. It doesn't matter if that DR is 60% or 80%.