Plain answer: If the content you and your users generate is great, it will boost your site.
If your content is poor, you won't see a difference.
I am quite sure it is not about the software you use, but the content it holds. Google is always stating this, and because most of the people use their search engine, you should follow it. Of course good content makes sense anyways...
Kind regards,
Kai
PS: I created a new project for Lithuania Klausimai ir Atsakymai - Klaustukai.lt and pay a writer to create unique content. The project jumped from nothing to Alexa Ranking 3,4 Mio within 3 months. As you see it might take some more time, even if you have great content.
