The latest TB with install directory measures 118 MB. Prestashop 1.6.1.11 only 74. I wonder what makes the difference. Even more puzzling perhaps is that Prestashop 1.6.1.10 measures only 61 MB on my system.
Similar effects play with updates. Updating a Prestashop to TB increased its size with nearly 120 MB.And that does not include the backup.
A large file size means longer up- and download times of the shop. It also makes that it takes longer to search a certain code fragment.