Btw., some installers are very smaller than the old one. As example, the new Fallout installer is about 30 MB than my old one which I downloaded at the Fallout promo (over a year ago). Any special reason for this, like a new Inno-installer? Or are stuff like the manuals removed from the files. Will check this later.
Edit: It seems ScummVM-games like Simon the Sorcerer are unchanged, what sounds logical. The same should also be for DosBox-games, but I will check this later.
Edit2: Downloaded Duke3D and the installer is changed. I downloaded the game shortly after release, so maybe it was a normal update.
Edit3: Okay, this should be a new posting, but the new one was merged with the old one. Back to the topic: I rebackuped some of my games and there are some games with Win7 support but without any updates, so a redownload is not necessary. I also checked the file properties and it seems that gog changes the file version of the installer after each update (to check this: right click installer, properties, details).
It would be really nice to have a steadily updated list with all games and file versions, so everyone can check their backuped versions and don't need to download all files again.