Some general guix questions

[Divan Santana]

Hi great guix community,

1. What is the recommendations around when to install a package system
   wide (via guix system reconfigure manifest.scm) vs in your user
   profile? I'm confused if i3/various X packages and other desktop
   packages should be installed in one or the other? Or even the pros
   and cons of each. Is this in the manual?

2. One can install packages via a manifest or via a frontend tool like
   emacs-guix or helm system packages.  I like the former, because
   it's like your system is defined in a manifest and evaluated, and
   you can keep track in git etc, suppose infrastructure as code. But
   I like the latter too and I believe some others do too. Is there a
   way to get the best of both worlds here? Any thoughts on the matter.

3. If I run guix system vm --fallback system.scm I get a vm I can run,
   which is really awesome. If I then do a guix pull and guix system
   vm --fallback system.scm I get /another/ VM which I can run. How is
   the previous VMs garbage collected, I wonder?

Thanks very much,
--
Divan