I have 830lbs @ 66" worth of BB hanging off the back of my L2800, it is a beast. I have filled tires and that BB can pull my L2800 to a stop with the rippers down in hard clay.
My previous BB was a 500lb unit that the L2800 could drag with rippers and box down with never stopping the tractor.
My BB maybe a little too heavy for my L2800 but I wouldn't want anything else.
I also have never had any problems with a light rear end when I have a full load of any dirt in the FEL bucket like I did once with the 500lb BB.