I have been into different paths/directions. Some companies have a pretty clear vision on their Information Architecture and alway want some meta data applied to documents. Next to that they require the documents to comply to standards using document templates. In this case the content types path could be a very valid way. Most of the time I used the content type hub in order to distribute the content types and be available in all site collections. When you have influence on the sites and libraries created and the available content types in the libraries, you are able to manage this using content types. When new libraries are created by users the content types are not bind to these libraries and should be added manually. This could be a hard part.
At some companies we just created a central templates library and users were used to go there in order to get a template they needed at that moment. At such companies, meta data was of less concern. This could work out pretty well, in my opinion.
We also went another direction in using a 3rd party offering like iWriter for instance. Some companies start off in their Office application (Word, etc.) and want the templates available there. Tools like iWriter work more as an add on in Office applications and offer other rich scenarios too.
More information on iWriter can be found here: https://www.iwriter.eu
I have no further connection with iWriter, but used it at client projects.
Hope this gives you some point in the right direction.
