I also found myself asking this same question, and after careful consideration I ended up choosing LXC over Docker, and here are some reasons why:

    - LXC works fine on it's own.

    - Docker has it's own bugs, so you get all of the
      Docker bugs in addition to potential LXC bugs.

    - IPTables routing for containers to the outside
      world isn't that hard to manage.

    - LXC is simple and straightforward, and by
      comparison Docker is a convoluted confusing
      mess of additional layers of complexity.

    - LXC is already used in many real-world
      applications for operational software
      everyday.

If you want to know anything else about real-world usage of LXC, please feel free to contact me (jay at jaytaylor com), or check out my relevant project: ShipBuilder [1].

[1] https://github.com/sendhub/shipbuilder