I've been selling stereo equipment for years, and the sound bars are pretty good.
The Samsung is one of the best sounding on the market right now. It has good clear sound, the software to integrate it with the Samsung TVs is good, and the cordless subwoofer is seamlessly integrated. One note about the Samsung sound bar; If I remember correctly, it only has one sound input, which is an optical input. So make sure your TV has optical out.

The Sony is abysmal. It has good highs, and good mid-range, but I have literally never seem a Sony sound bar stay sold; you can't even hear the subwoofer, which is half the purpose of buying a sound bar.

The Vizio sound bar actually sounds really good. But personally, I would never buy anything Vizio; I see 'em returned all the time.

If you could find one of the older Samsung sound bars, those are even better then the new ones. They have build in DVD players, and they sound AMAZING. You may be able to find one online somewhere.