In theory, most EZTRAKs can be upgraded to version 5 or 6. The older ones I leave at 3.02 which is the first version with a screen saver. This statement does not include the southwestern versions.
Version 5 is very stable.
There is a new version 6 that corrects a lot of the errors of the original version 6. No, I do not have it (yet). Version 6 does have engraving and can import DXF files(very limited).
George
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)