Trying out some Shimano PD-534's. Having knee pain and I think insufficient float and the wide platform is contributing. The pedals have hurt from the first mile.
They are on a new bike so even though the setup matches my pro-fitted good bike, there are a few other factors to consider. Different frame, cheaper components. Obviously the pedals are the cheapest thing to swap out to see if that fixes it.
Never had any knee pain on my Shimano MTB 540's except when I am grinding cadence < 35 on very steep standing climbs.

I've had the PD-534's for a while. They were hard to get used to until I loosened the clip tension to pretty sloppy. Much easier to clip in/out now.