it seems that directory links tend to increase their value as the page they are in increase the page rank. While Blogs links - even if posted on High page rank sites - After the first days on the main page are archived to a page not even cached yet and so they loose the value they gained when first posted. is this so ?
I have asked the similar question before in another thread. Some believe links from blogs are better because of contextual, assuming Google likes these links better. If blog has categories with PR, then shouldn't this be better? So that archived posts fall under a category. I'm in the process of building those sites now, expecting to get good PR on those by the next update.
IMO, your link profile should include a mix of authority directories, niche directories, blogs, personal pages in your niche, forums in your niche, etc. Don't put all your eggs in one basket.
Definitely blog links. Directories, maybe the biggest 10, but that`s it. I strongly prefer a small link from a blog, instead of an useless link from a directory
There are just as many splogs as there is spam dirs, I definitely wouldn't say directory submission is dead. That's a pretty harsh statement.