I forward my domains. I'm not really sure why but I find this seems to give me better traffic.
When I used their name servers I also had that problem with it saying '1.5 million domains for sale etc, etc' in the description. I changed one particular name to forwarding from name servers, changed the description to something more relevant and enticing and the traffic increased fourfold from google. Nothing to do with
SEO as the position was the same, just the fact that the description made the user click.
I have asked the name servers vs parking question to sedo direct in terms of
SEO and, I think, they said name servers but as I remember I don't think they gave a reason. I'll try and dig out the e-mail....