Sorry never used it before, so I can't really comment on it. Personally, I think it saves you a lot of time and works if you really can spend that much for the submissions.
I have used Submit Suite before; basically what it does is SPIN your article into many variations with synonyms for common words. It's automated and really quick. The only downside is that you have to manually proofread the new SPUN article in order to ensure proper grammar and flow. In my experience it's useful for submitting variations of an article to 'lesser' article directories. What I do is submit the original to Ezine and then spin my article 5 times or so and submit to the other directories.