Hi Colin,
I have 3 different brands of 500Hz filters (Kenwood, Yaesu and Icom) not really feeling the Yaesu one wider than the others. But this is just a personal perception and others might have measured/tested/compared them with lab equipment, while I’m only talking about my personal feel.
The filter I have used less is the one in my Kenwood TS-940S, as I find far more comfortable and effective the use of the CW VBT control instead of the 500Hz CW filter.
I very much miss this CW VBT control on all my other rigs, as it’s the best to get rid of the noise and let you pull extremely weak CW signals out of the noise floor.
73,
Guru