Before someone asks: yes, this is not the complete work as offered in DL/Fanza. Files uploaded belong to the "lightweight" version included with the download, at "only" 2173x3024 resolution and 822 Mb.
So while we're still getting digital mangas at ridiculously low resolutions, the author decided to offer the original work at 4346x6047 with a size of 2.9 GB, amounting for a total of 5.86 GB due to the inclusion of the No-Text version (no lightweight alternative for that)...which seems completely overkill for a 300 pictures CG set, if you ask me.
I finally decided to go with the lightweight version, but if anyone is interested I can upload the rest of the files either here or in a separate gallery.