I think it's both, especially in the local sector.
If talking local keywords, like "City Dentist" Google is definitely giving ranking weight to directories and niche specific sites. I've seen some very competitive keywords in the local market rank only because the client had a site for years and was in all the local directories and niche specific directories. 3 years ago, you'd look at this link profile and think "Huh...how?", but nowadays that's become more and more a quality signal, so I say you need both.