Libraries API allows the use of a central repository of libraries under
../sites/all/libraries and this makes maintaining them easier. Plus you don't need to have the same library (in our case the same .js plugin) more than once in case two or more modules are using it.
If the user doesn't have the Libraries API module installed, then you can have it gracefully fall back to the old directory. I believe it is becoming more of a standard though (like cck and views), so most people will be installing it anyways I guess.
Thank you in advance for considering this.
PS: Thought I should list Libraries API's features here in order to support my case:
- The same library can be shared by more than one module.
- The same library can be shared by more than one site.
- Ease the process of upgrading a module that requires an external library. Just replace the module folder with the new one. No need to move the contained library out and back in.
- Preventing incompatibilities due to having the same library installed more than once in different versions.
- Central installation instructions (widget) to help users figure out how to install.
- Library classification.
- Handling of dependencies between libraries.
- Library version detection.
- Runtime control of library availability.