When using TDS Classic to install items, Lightning Mode skips the install of an item if the crc of the revisions match. This helps to improve the speed and efficiency of both deploy and sync operations; users of RAZL will recognize this feature, which performs similarly in that product.
When there are large numbers of TDS projects, users can now push everything in the projects to Sitecore at once; items are pushed in the correct order and pushes only items that are changed. Solution Wide Sync is a huge benefit when working with solutions that contain many TDS Classic projects, as most projects using the Sitecore Helix framework do. This feature works best when used in conjunction with the new Lightning Sync setting.
Turning on the Lightning Sync setting will allow sync operations to use the new Lightning Mode feature, which is especially helpful when syncing over the entire solution. This is a critical speed improvement given the increasing possibility for many item comparisons in a single Sitecore Helix project.
This new setting in TDS Classic 5.7 can be used to enable Lightning Mode for all deployments that utilize the TDS Sitecore Connector, improving their speed and efficiency. This includes the TDS Classic 5.6 feature Quick Push. Internal tests show 40% improvement in Habitat deployment over typical non-TDS solutions.