I use an INRAD CW Filter, really nice for CW, a bit tighter than the stock 500 hz. At the moment, looking to get another 920, in trade for my new 7200. I just love teh 920 that much.
So I gather you like it? I just bought one today (but yet to receive it) Will sell 2 of my 3 Ft-450s to pay for it :-) Hope it's a good move. Will then just mainly use this & my favourite - the JRC JST-245...