- It helps .
- It uses its own custom table, when folks are asking for a more generic relationship solution that works better with Views, etc.:
- Placing it in contrib will allow it to depend on other contrib modules to provide the desired behaviour. For an example of how this could be done, see http://drupal.org/node/1176828#comment-4818914.
The one problem I noticed with my example above is that is doesn't provide any Back/Forward links. However, a small function placed in Views Tree could return the next or previous item.
Relation could probably be used as well, but I'm not sure how far along it is.