If you want a more ‘stable’ experience - it’s better to install from the official repo with pacman whenever possible. Likewise on the AUR, pick the non-git package version.
There is no best way. It is all about personal preference.
As for the differences between AUR versions, here is how it generally breaks out:
package - This is the standard version of the package. If the source code is available, it should be built on your machine based on released version of the product. If no source code is available, it should be a binary of the released version.
package-git - This is typically built off the latest source code in the source repo. It may have bugs. Depending on how the maintainer manages the package, you may need to pass a devel flag to your AUR helper to get proper updates.
package-bin - This means the package is downloading and installing a prebuilt binary.
Here is a post where I compare flatpak with the AUR.
There is also no problem with using AppImages but they will consume extra disk space and won’t get updated with your other packages. Some of them are self-updating, others are not.
My personal choice is usually repo>aur>appimage/flatpak but I make exceptions some times. I will never use snap because of the intrusive telemetry collected by Canonical which cannot be disabled.
You don’t actually need that package, it is just makes it more convenient.
AUR has pretty much everything and is transparent.
I find appimages and flatpaks most useful for older software that either fails to run any more on a rolling distro (ie dependency breakages), or has introduced functional changes you don’t want.
I’ve seen Ermanno who post YouTube videos on Arch Linux explained that he prefers the git-clone method to install AUR packages vs simply using yay AUR helper.
Any specific benefits of this?
I suppose one benefit is that you can see the code in the install file and what’s in the pkgbuild folder?
It gives you more control but it adds effort. Especially when AUR packages have AUR dependencies.
Your AUR helper should be able to show you that as well. The better AUR helpers can even show you the diffs between those files and the last ones you installed so that when you are updating, you only review what changed, not the whole file.