When comparing Yaourt vs Pakku, the Slant community recommends Yaourt for most people. In the question“What are the best AUR helpers for Arch-based Linux distributions?” Yaourt is ranked 5th while Pakku is ranked 10th. The most important reason people chose Yaourt is:
Yaourt commands and flags match pacman, so it is immediately obvious how to use it.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Equivalent to pacman
Yaourt commands and flags match pacman, so it is immediately obvious how to use it.
Pro Colored output
Pro Adds seamless access to the AUR
Pro Can be set up upgrade your system with no additional prompts
Pro You can adapt PKGBUILD to your needs during the (pre-)installation process
Pro Supports backups
Pro Auto removes build dependencies
Has option to auto remove all unused build dependencies.
Pro Wraps pacman
Installation or updates of official or aur packages can all be done with pakku.
Pro Uses pacman interface
Easy to use for anyone familiar with pacman.
Cons
Con Insecure
More information here.
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.