Ronen had about the same thoughts and questions that I would raise. What are your needs, and exactly why are you discarding those two technologies that you mention?
Two things that I'd like to add to the article that was pointed to, which I didn't found discussed much in the article are:
Do you need to know who did the modification? Many of the techniques don't capture that.
How easy is the audit log to manipulate? For instance if a trigger logs to a table, then anyone with sufficient permissions can modify that audit log. And a sysadmin cal always do anything inside a SQL Server instance.