I disabled qubes-gui-runuser yesterday with the following side effects:
- xterm doesn’t work (of course), but console works fine (it takes a bit longer to start the disposable VM, but it’s not big deal)
- the netmanager widget doesn’t display on the top bar anymore. Even though I like to know what wifi network I’m connected to from time to time, it really don’t mind reducing the memory footprint on that VM by another 100MB by losing that visual gimmick
Total memory savings between X and the network manager widget are about 200MB or even a bit more.
Since my problem is not disk, I did not uninstall X or any packages, just prevent qubes-gui-runuser from running (or just kill it after it runs).
I may seem stingy, but still remember when my computer only had 1MB of RAM in total and I could only use 640K as normal memory (and do acrobatics to get another 120KB or so in EMM)