Oh thanks for the dpi increments!
Maybe the sensor received some tweaks in the way of something like lift-off distance and tracking speed as well?
I'm still confused about this one, we'll hopefully see some comparison reviews once it's out.
the FK had a different sensor than the FK1 and FK2 have.
the faulty 1000hz that the FK had is fixed since the FK1.
the sensor in the FK1/FK2 has a low LOD of itself, so they could ditch the custom lens they had in the FK.
the LOD on the FK1/FK2 is slightly higher than the LOD of the FK, but it's still very low.
as said, the FK2 is the FK1 internals in a FK shell. so if you own a FK and a FK1, you can make the FK2 yourself.
the internals of the FK were good, but the internals of the FK1 and FK2 are better.
unfortuantely the button latency is a bit high but, for most people, this is not really a problem.
@Lpwl
the FK also had 125hz as an option.
@munch
all FK mice have the same switches.