I agree that quality links do give more of a bang than your usual manual link building methods, however from a link building perspective, there are 2 major issues;
1- Quality links, that are editorially given are much harder to come by than a few hundred directory listings.
2- The quality links you manage to get are probably not going to be anchored with the keyword you're chasing, therefore your ranking ability is hindered.
In my experience a site with 1000 'low' quality links anchored with the target phrase, will always beat a site with 50 high quality links anchored with the name of the site or other random terms.
I think the perfect combo is to target low quality links manually and then focus on creating quality content for the higher quality, more editorial type links.
