I don't think having your
website hosting on a dedicated IP addresses would make a huge difference in the
website hosting's SERPs. It is also believed that sharing an IP address with known spam or adult
website hostings raises a warning flag with search engines, which results in ban of the entire IP address from their index.
Majority of
website hostings on the Web are hosted on shared IP addresses, furthermore SEs are capable enough to ban anything on the basis of illegal techniques adopted by the
website hosting owner instead of banning an entire IP neighborhood.