Guest Posting is the best way to get backlinks from authority websites if done well. Article submission is quite like guest posting, except you are submitting the article in a directory rather than a blog.

Well said. But now a days Guest blogging is better that Article directories.

but many top blogging sites have stopped their support to guest blogging.... as Google seems to have negative thought over GB.

Yes. I completely agree with you.

I think guest blogging is helpful for getting traffic.

Many still use this method to drive traffic to their site.

According to me guest posting is best way to generate quality backlink in terms of draw traffic and rank position too.

Guest Blogging is helpful for getting traffic if you are using quality content.