When comparing Yaourt vs pikaur, the Slant community recommends pikaur for most people. In the question“What are the best AUR helpers for Arch-based Linux distributions?” pikaur is ranked 4th while Yaourt is ranked 5th.
Ranked in these QuestionsQuestion Ranking
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 Upgrade -git, -svn and other dev packages
Pro AUR package names in shell completion (bash, fish, zsh)
Pro Using systemd dynamic users if building packages as root user
Pro Show unread Arch news before sysupgrade
Pro Interactively handle common build problems (like untrusted GPG key or checksum mismatch, wrong architecture)
Pro Can install packages even when others fail
Sometimes when building multiple unrelated packages, the failure of one means that none get installed. With this helper, it will not only ask you what to do during a failure, but you can skip the package all together without having to restart.
Pro Remove make dependencies on completion
Some AUR packages require at times dozens of dependencies solely for the build process. Usually, once the build process is done, they stick around without purpose. This helper automatically removes those dependencies once all the builds are complete.
Pro Retrieve PKGBUILDs from AUR and ABS (-G/--getpkgbuild)
Pro Build local PKGBUILDs with AUR deps (-P/--pkgbuild)
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.
Con Bad split packages support
Con Splits pacman -Syu to -Sy and -Su
-Sy (to refresh package list first) and -Su (to install upgrades after user confirmed the package list or has been altered it via [M]anual package selection).