I would say that Gog is without and Steam probably with Securom. But the game itself should be the same.
Link please, otherwise I highly doubt the validity of this. Steam itself is the DRM, anything with Securom is undoubtedly added by the publisher who decides to sell games via the Steam platform that already have Securom included in the installation files of every infected game in their catalog.
That said, I'm just recently returning to Sacred 2 from a long absence away but when I first fired up the game I was greeted by the friendly auto-updater for the CM patch which was able to download the latest patch and complete installation regardless of the number of errors it flagged along the way, so I assumed since it was able to complete, those files weren't really necessary otherwise the patch couldn't be installed, right? Yeah, not so much. I really do think that the auto updater for the CM patch is more of a hindrance than a help right now, especially if it just continues with installation even after errors are found.
I ultimately got around this issue by verifying integrity of the game files and then applied the patch manually. I have also deleted the auto-updater because as a returning fan of Sacred 2, it really didn't help me much at all.