I'm upgrading from elasticsearch 0.90.10 and NEST 0.12.0 to elasticsearch 1.3.4 and NEST 1.1.2, so I'm not sure if this was actually part of NEST 1.0 or if it came later, apologies if it did come later.
http://nest.azurewebsites.net/breaking-changes.html mentions DocumentsWithMetaData was renamed to Hits. In addition, and this isn't mentioned, Hits was renamed to HitsMetaData.