I haven't experienced any BAD regarding lowering my BA, but would recommend lowering both the front and the rear and not just the rear alone. The added benefit of, for example, lowing the front end with (say) Progressives lowering kit (front springs) is the reduction in front end dive when braking. Your lean angle will decrease a bit, but this hasn't caused me any problems as I am not a knee dragger anyway. I haven't experienced any handling issues either. I lowered the front and rear between 1 1/2" - 2".
I'm also sitting about an inch lower with the Corbin saddle. (Me likey)
