If I understand you right, $399 is a bit much for sound quality improvement? If you are willing to spend more than that, there are better sound quality solutions - even in sound bars. If that's the top of your range, I think it's a question of whether your built-in TV speakers really bother you. What are you trying to accomplish? Volume? Surround or simulated surround sound? Better quality sound and voices?
I was just a Boston training seminar and heard the TVEE2. With the included woofer ( not really a sub ) I was quite surprised. Sounded rather nice for what it was. The cool thing is that the remote receiver in it is learning, so it works with your existing remote.