Only the "NWN HotU v1.69" Critical Rebuild patch works properly. All others give me a "You can't use this patch with your version of Neverwinter Nights" error message.
The Bioware download page lists the HOTU patch is also for the Platinum and Diamond (the one GOG sells) editions.
Ah, ok. Still, as incomplete as the GoG version is, I wish the other two patch packages would at least go over the files they're meant to patch, for posterity or something. You know, just in case there are actually files that are found in them that aren't found in the HOTU patch.
On the other hand, if all files that are going to be patched can be found in the HOTU patch, then I guess I don't need to worry about the other two.