How good is surround sound via headphones really? [closed]

I'm looking at purchasing an Asus Xonar DX 7.1 sound card which has..

Dolby Headphone: Delivers a realistic and spacious 2-to-5.1 surround or 3D positional soundfield over any set of stereo headphones

Has anyone used something like this before? Does it provide any real value with a FPS shooter like Bad Company 2? I play hardcore mode so knowing when someone is behind me would be nice..

I agree with the above comment about this being a subjective question. With that being said I will provide you my personal opinion after having used 5.1 digital surround sound headphones for gaming for around 2 years.

I can't recommend them enough if the money isn't an issue. The headphones help substantially in a couple different ways.

First: The sound clarity is amazing. You'll end up hearing things you normally wouldn't have heard. Footsteps seems amplified and its easier to tell the direction of gunfire.

Second: Direction. In addition to the location of gunfire, the 5.1 surround sound makes it easier to identify the direction of the footsteps. This helps prevent people from sneaking up on you.

Third: Late night gaming. It's useful to play a FPS at ear splitting volume but never wake anyone up. On late nights your significant other will thank you.

Finally: The most important aspect of gaming headphones. It blocks out ambient noise. This is true with any headphones and will greatly improve your game. Whether you realize it or not your body focuses on ambient noises and by blocking them out I have found my concentration for the game is greatly improved.

As with any other recommendation, take this with a grain of salt. But I have personally found gaming headphones to be invaluable in my FPS game.

Speaking generally, I have used virtual surround sound in FPS for a while, specifically a Razer Megalodon, and found it to be an impressive improvement over traditional stereo headphones.

Specific to your combination of game and sound card, this review from ThinkComputers covers the use of the Xonar and BC2, saying the following:

While in Battlefield Bad Company 2 upon first getting into a new single player game I was able to notice a big fps difference, Along with the sound being a big improvement over the onboard sound. While playing the game I felt almost like I was in the action with having more bass and better directional sound being able to pinpoint enemies.