Can’t say if better but my impression from outside the GuixOS community
is that Guix is well maintained. Also, its configuration language,
Guile Scheme, is a full-fledged programming language that allows you to
configure all your “stuff” in a GNU ecosystem. This “learn one lang to
rule your system” is more attractive to me, than what NixOS has (a weird
config language that only works in the scope of configuring NixOS).