Article marketing and anchor text... how much link juice is the anchor getting?

It also depends on the article directory that you are getting the links from. ArticleDashboard will give you a lot of link juice if you get your article to a PR2 or PR3. Their articles don't have many outbound links on them so you will get more juice. Ezines have a lot of outbound links and that waters down the link juice significantly.

On the flip side I have many Ezines that naturally rise to PR1,PR2,PR3 very quickly because of the traffic but when I analyzed my backlinks recently I saw that PR2 ArticleDashboard articles were worth about twice as much juice as a PR3 ezine.

but again it's really hard to quantify because noone knows the exact values Google gives to links in relation to where it may appear on the page and relevancy of the subject matter with the anchor text. Matt Cutts from Google does give an explanation of the basics though in a video and shows how the value of the links is greatly diluted with more and more outbound links.

You can go for quantity, quality, or both. I go for diversity because you never know what the next Google algorithm change could do if you are too heavily vested in one type of link.