Dreamteam67: Depends on what patch you are talking about. If you mean patches from the game developer, then yes, the GoG version is the "final" version released by Troika Games and Atari. THe GoG version runs and is playable, but you will encounter plenty of bugs ranging from trivial to crash-to-desktop. Imo, the experience is akin to being a beta-tester.

The "patch" that came later was a third-party patch made by a fan group who called themselves Circle of Eight (also known as the Co8 mod patch). This patch is not supported by Troika nor Atari nor GoG, it does however fix the most serious bugs plus adds in a bunch of new content, most of which expands and extends gameplay beyond the ToEE original adventure. In many ways it is more of an expansion than just a patch, although you can still choose to play the "vanilla" adventure with all the bug-fixes but without new content if you want.