What's the advantage of R&S VISA over PyVISA-py, which requires even less setup?
The xyphro adapter presents itself to PC as a USB device and in PyVISA-py, there are several VISA functions that are not implemented for USB. These include clear(), read_stb(), and assert_trigger() all of which can be necessary to take full advantage of an instrument's remote programming capabilities. read_stb(), assert_trigger(), and the various "event" functions in particular are often necessary to get the fastest possible communication with an instrument.
To install R&S VISA on the Pi on Linux, all I had to do was download it and run:
sudo dpkg -i rsvisa_5.12.9_raspios_buster_arm64.deb
Running the installer on Windows or Mac is pretty quick too, so I would argue the setup effort is minimal.
R&S VISA also provides the Tracer app, which is super handy for debugging. Just open it and start monitoring in the background while your own application is communicating with the instrument, and you can watch all the raw traffic between your application and the instrument. Great way to track down issues in your GPIB command sequences, especially for the quirkier instruments.