Some Comparisons of Sign Tools - 2
Comparing Authenticode to Netscape Object Signing
Netscape has finer-grained access to resources. Microsoft simply gives an access level instead of dealing with privileges, which is easy for developers.
Microsoft's Authenticode is more simple for end-user. Netscape prompts to user to grant permission for each privilege request. User has more control but may get exhausted with unrelated security questions.