wheel - 9:51 pm on Aug 1, 2011 (gmt 0)
They're pretty much the only type of links I do chase. I do absolutely no article submissions, and I only do blog guest posting on blogs who are of sufficient quality that they basically don't do guest posting, i.e. where most people would be unable to get a guest post.
It's not the only thing that works, but don't discount it as a strategy.
In terms of competitors, I love getting links from competitors. I helped an old dude (guy in my niche) rebuild his website last fall and got a link from a 10+ year old pr4.
Last week I had an offer to do the SEO for a keyword rich domain in my niche - one of the old originals. Guy's had the domain forever, Yahoo actually made them an offer back in the late 90's for the domain. They offered me a cut of the business. I declined, but they mentioned that they loved the wordpress layout on my site. Since it's a custom design that I bought and own the (C), I offered them the use of it on their site, under two conditions; one they buy their own copy of the one image the theme uses, and two, they give me either a homepage link, or they give me a full page of content with my own links from within content.
Nothing that others couldn't do. We all have to do our cost/benefit determination to decide if it's worth chasing these types of links.