Specs
Pros
Pro Equivalent to pacman
Yaourt commands and flags match pacman, so it is immediately obvious how to use it.
Cons
Con Not maintained anymore
According to the Wiki page of Archlinux, Yaourt development is stalled.
Con Does not perform clean builds
Environment variables may get carried over while building a package, preventing successful building.
Recommendations
Comments
Flagged Pros + Cons
Con By default requires user input separately for each build instead of once before building them all
Yaourt will ask you whether you want to alter the PKGBUILD before building a package. However it will do this once at a time, meaning that it will let the user modify the PKGBUILD, build the package, let the user modify the next PKGBUILD, build the next package etc.
This leads to the user being forced to constantly watch the yaourt command whether it requires input to proceed.
You may completely supress the option to view and alter the PKGBUILDs by passing --noconfirm to yaourt.
Con Breaks when updating AUR packages as root
Does not gracefully drop permissions when executing makepkg, which fails when running as root.