As mentioned, the Kent and Fiocchi factory spreaders are pretty heavy recoiling. I will say, if you're a choke tube changer, IMO they offer nothing in patterns that you can't get with cylinder tubes or threads. The only advantage is the option to instantly try or abandon them them in the middle of a target station. With tubes, once they're in you're committed to your choice for the whole sequence.
I haven't tested any Polywad factories, but I've experimented with their discs in handloads and found they're pretty versatile.
I think the factories are only available in #8, which may be fine, but you can handload #8.5 or #9 if you like. Afterall, their intent is for very close targets and you can lower recoil with lighter loads of smaller shot. I'm shooting tight, fixed chokes in an 80 yr old Fox and I've found I can tailor spreader loads that give great results at relatively low pressures and velocities as low as 1100 fps.
