I was considering starting a thread on the topic since I just bought one. I have no experience with soundbars, so I can't offer any comparisons other than to a full 5.1 set-up.
I just bought a UN40C6300SF for my bedroom and was disappointed with the thin sound from the TV's built-in speakers. I did not want an elaborate set-up and wires so I decided to try a soundbar. Since the finish on the HW-C450 matches the TV (glossy black with clear accents), this was my natural choice. The salesman at BB insisted the two Samsung soundbar models were identical which makes no sense to me. I assume the HW-C451 has a metal finish to match the higher-end model TVs.
(Sorry about the glare from the flash.)
The speaker looks good with the TV. If resting on the same level as the TV, the speaker would obscure the bottom of the TV frame, which I did not like, so I placed the TV on top of a DVD player to raise it slightly above the speaker.
The glossy black finish is a fingerprint and dust magnet and I somehow already managed to scratch the speaker finish. There is a touch-control on the top clear-plastic bezel which is cool, and a basic remote.
The sound is very good considering the small footprint. There is nice detail and separation with a wide soundstage, but I don't experience any of what I would call "virtual surround" effects. By this I mean I don't experience any sounds that seem to come from outside of a stereo soundstage. This could be due to the environment. As you can see, I have the speakers and TV elevated on top of a tall dresser. There is no guidance offered on positioning or set-up. Advice from others would be appreciated.
Sometimes, deeper male voices seem to originate in part from the sub in comparison to female voices which come from the virtual center speaker. I find this contrast disconcerting. The SW volume can be adjusted, so perhaps I'll find a better setting. There is also a dynamic range compression, but the manual does not really tell you how it works (or even what DRC stands for) only that you can set it to minimum, standard and maximum. I assume maximum offers the most compression.
There are 6 "sound field modes" aside from pass-through. I haven't played with these much since I tend to avoid these effects and don't really enjoy messing with settings as I switch programs. They seem to affect how much focus there is on voices. "Cinema" seems to create a theater-like reverberation effect. Other choices are "music," "news," "drama,""sports," and "game." The manual could do a better job of explaining what these do.
I used the optical connection which allows the speaker to turn on and off automatically when the TV is turned on and off. The wireless sub basically set itself up, though it did not seem to lock in right away. I turned the TV on and off and that seemed to help.
The off display light issue that people complained about in an earlier model is gone. When the speaker is off there is only a small red light similar to the one on the TV itself.
Update: Moved the sub further back into the room (it had been up front next to the dresser) and this resolved the issue of separation of male voices and also seems to have enhanced the soundstage.
There is also a "smart volume" feature for evening out volume levels which I haven't really used yet (I don't tend to watch many commercials) and an audio delay adjustment (0ms to 300ms) to use in case there is a video time lag.