Don't know much about it I swapped a 6" same make Vertex for this 4" one, stripped it out, it is as new did not see any wear, fitted it out with some thrust bearings no backlash or tight spots so I guess I was lucky, (but they are well made) built it back up and away we go, not used it until last week then found the lost step problems.
Had a few settings to work through in Mach3 but now it works great, found a good program for wrapping, CNCWrapper so easy once you have your Gcode.

Not obsolete see here: http://www.chronos.ltd.uk/acatalog/V...cessories.html