The First Methodist Church and the Rainier Club are having a major impact on this project, but during design review the architects were lauded for their careful consideration of both. It appears from the PDP website that zoning remains an issue. Here's the design review report for this project:
http://www.seattle.gov/dpd/AppDocs/G...gendaID942.pdf.
It is being developed in the unrestricted height zone, so, it could indeed reach 700ft. Haven't found any published heights for this project.