Bax is beast on the low end, especially post compression. Sometimes you want to the peak right at a certain frequency to maybe make the kick pop a little bit without lifting the overall bass too much. I'm looking at adding a 5500 to my rack. 5500 for bell peaks, primary on the low end, my massive passive
mastering for mids (amazing), and then my bax for shaping post compression. Also great because they are all switchable. But I really need a console (Dangerous Liaison perhaps). I think the 5500 is more important right now.