Thanks fishing and Bigman, sometime some RSS directories copy the exact content and publish to their and that is also count as duplicate content in eyes of Google, so I believe not to submit cause may RSS directories will be the next target for google eyes..

My rule of thumb for now on.. this is very much part of any campaign I start...first thought, is this just a scheme to better my rankings or is this going to add value to someones day....if it is going to add value to someone....sure...if your sole purpose is to get backlinks....try another stratetegy....backlink manipulation is gone and gone is gone and it probably will never come back....google now is looking for quality and quality is going to rule the nest and all the rest will fall out of the nest (damn I shoul be a poet..lol..lol)

There isn't anything wrong in submitting to that many directories, I use them myself but never have that many to post to.