I don't think Super User is too broad, but:

1.  The Opensource alternative proposal may be way too narrow.  Would I go there *only* to ask for alternatives to X paid application, or would I also be able to ask questions on how to use the open source alternative?  If it's the former, then it's too narrow.  If the latter, then it duplicates a *lot* of the purpose of SU.
2.  The Computer hardware proposal is about half of what Super User is for, per the [SU FAQ][1], so I agree that it would be too close to duplicating an existing site.

Also, I think a lot of the questions that *did* make Super User feel a little bit too broad are now handled by more focused sites like [Ask Different][2], [Ask Ubuntu][3], and [Unix & Linux][4].


  [1]: https://superuser.com/faq
  [2]: https://apple.stackexchange.com/
  [3]: https://askubuntu.com/
  [4]: https://unix.stackexchange.com/