How do you determine a quality link?

[Woodstream]

I have a question about quality of links I'm seeing with my linkbuilding program.  I just noticed that my 2nd ranked backlink contained the keyword as the username with a link back to my site.  There was no relevant text in the comment itself with the keyword linking back to my site.  My question is this good practice?  I wanted to get your opinion of these kind of links for a linkbuilding program.  Here's the backlink and our keyword is the username Cat Control: http://bytesizecss.com/blog/post/fix-haslayout-with-one-line-of-css.  It looks like everyone posting on this page is just linking their username back to their site...  I'm not an SEO expert by any means, but if everyone is doing this same type of link building on a directory type page such as this.  Could these type of links  eventually become a target like what happend with the farmer/panda update?

[EGOL]

The easier it is to obtain a link the lower it's value. Great links are like the Marine Corps Officer's Sword.... "Earned. Never given."

[JoeAmadon]

In my opinion, these sort of blog comment links are pretty low quality. A handful of these shouldn't hurt you but don't expect them to bring a lot of value. It is a pretty common practice, because it is such an easy link to acquire. Which is often one of the things to consider when evaluating the quality of a link; how difficult is it to acquire a similar link? Some easy links will be of decent quality, but not many. Other things to consider when evaluating the quality of a link are:

Page Authority.

Number of outbound links on the page. The more links leaving a page, the more diluted the link juice will be.

Relevancy. Would it ever make sense for a user to travel from that page to your page and be satisfied with the experience? Users don't have to use the links, but this is a good way to judge topical relevancy.

Anchor text. The more descriptive the anchor text, the better. Expect poor anchor text ("click here") on some links, but good anchor text is a definite bonus.