I am 5'8", 195lbs, and 8% BF. I don't think I have ever been over 15% and was down around 2% to 3% a couple years ago and weight was 170. Tend to keep it around 195 to 185 at 10%.
6'0 215. I'm by no means anywhere near big, but I have been up to 235 before when on and was not doing cardio at the time. I felt sluggish as hell. I think the most I'd ever want would be at lean 240 while still being able to run say 3 miles or so without dying.