If you really, really, really are set on the idea of storing the client on a central server, be warned that the typical failure symptom you will see when you push your network too hard, will be APPX clients "just disappearing" seemingly randomly. If you see things like that, or if processes that normally work randomly lock up client computers, and you have ANY clients ANYWHERE on your net loading appx.exe across the network, please set all clients to use a LOCAL copy of appx.exe and see if that takes care of the problem, before you call APPX Technical Support.

If you are that concerned about the maintenance headache of updating several dozen clients' copies of appx.exe when a new version comes out, consider investing in one of the network software management packages out there, like Microsoft's SMS. (This isn't an official APPX "go out and buy it" recommendation, just a word to the wise regarding something you might want to consider.)

APPX doesn't want to run my APPX_PRT_SCRIPT. What am I doing wrong?

Nothing, most likely. However, current versions of APPX blindly pre-penned the APPXPATH to the value of APPX_PRT_SCRIPT. In order for APPX to properly invoke a replacement APPX_PRT_SCRIPT:

        - your replacement print script must be in the APPXPATH directory
        - you must set APPX_PRT_SCRIPT to the file name, not including
          any directory or drive letter information in front of it (for
          example, you might set APPX_PRT_SCRIPT=myprint.exe)
        - APPX_PRT_SCRIPT must be set ON THE SERVER (not the client;
          remember, when connecting to APPX Presentation Server, the
          SERVER controls the printing), along with APPXPATH and the
          other standard variables.  Generally this is done from
          Control Panel / System / User Environment.  Remember to
          reboot after you change this.