Hello there, answering your questions:
1. i am not sure whether i can reveal the articles directory here or not but both article directories that you stated had been doing good for me.
2. yes, i have my very own of favourite 5-6 article directories. also there are certain directories that accpet certain niche contents and what i did is only submited to the related ones.
3. the max i can get from a single article directory is 250++ visits/ month. not all article directory can generates such figures though. i consider the number is pretty good as people who visit my website after reading my articles should be quality traffics (well targeted).
4. .....are you asking questions here?
In general, i would recommend article submissions as one of the alternatives you can apply when google or msn or yahoo doesnt love you. it takes lots of extra work but the viral effects can be very good.
Meanwhile, i would like to know about the effects of article submissions to SEO. as i am doing article submissions along with other SEO method, i cant measure how effective is article submission to search engine ranking. from the viral effects (extra link popularity when scrappers/bloggers copy your writting), does it give positive effects to the website rankings, especially on google? anyone here manage to get sufficient ranking boost by just submitting articles? if so, how much articles had you submited?
Appreciate for any kind of sharings, thanks.