Which is best when creating articles for article directories?

I'm creating articles for several products. The articles will be spun and submitted to article directories manually.

Is it best to create an article about the specific product or a related theme?

It doesn't really matter as the content in the article is just camouflaged fodder for the article to get accepted by the article directory as well as giving the search engines a reason to crawl the url and see the backlink.

So an article about blue widgets with a link about blue widgets carries the same weight as an article about scissors with a link about blue widgets?

I thought google was smarter

It's not the article that gets you the backlink, it's the anchor text.

The content of the article gets you published and crawled; the anchor text gets you the backlink which boosts your site.

I could write an article about the filing cabinet in my office and put a backlink in the resource box about coffee... they tie in nicely... or I could put a backlink in about my car as I use that to get to my office... or I could put a backlink in about the local supermarket as we shop there to get food for lunch in my office... or I could put a backlink in about trains because there are train tracks near my office.

It's darn near impossible to say one thing does not relate to another in some fashion.