Just wanted to clarify that it is possible to just download the patches without needing to re-download a full installation. You can login to your GOG account online, then click on your D:OS game. Once you reach the page, ensure that your GOG.COM DOWNLOADER is set to OFF. Once you do that, you will see links to download each of the four D:OS installation files, as well as three patch files which can be used to update D:OS installations which have been previously patched:
Patch 1.0.107+ to 1.0.130 70 MB
Patch 1.0.74+ to 1.0.130 1.5 GB
Patch 1.0.130 to 1.0.132 (hotfix) 4 MB
I used the above to update my 1.0.107 version to 1.0.132 without re-downloading the whole installation.
Looks like GOG should have ensured their downloader allows downloading of specific patch files, but it's a small albeit annoying oversight.
Hope that helps somebody who bought this great game on GOG.
