Taking a break from the firework show and ran across this comment on EOS linked-in site. The first question is from someone that commented and the EOS reply. This was from 1 month ago.
Comment- What are the main differences with the M-280 400, apart from the obvious revamp to resemble the M-400?
EOS - Electro Optical Systems Carlos - the M290 shares the M280's build chamber and basic operations. The areas of improvement include process monitoring (now and future products), a new and more intuitive software interface and a new filter system better suited for industrial production.
Anyone care to speculate into what process monitoring their planning on integrating? Maybe they have their own? Happy Independence Day everyone!