I thought the Agent story was excellent. So much better than the Jedi Knight story that I'm currently playing through (not that the Jedi Knight story is bad, just the Agent story is better)
Each story has a different focus. The thing about the knight story, is that it's underlying theme is the slow seduction of the darkside, which means it has to build slowly and the most extreme danger is internal, unlike the agent and warrior stories where a sense of real, physical danger is present from the beginning. But yeah, the agent story is amazing.