I bought the Pioneer 5.1 to serve a dual purpose. One as it's original intent as as home theater system and two, to work as a basic CD player and FM radio for the living room. (My expectations as a sound system were not high and not primary.)
I am very pleased with the system. The features and functions are numerous and provide a large array of options for listening. The sound itself is also very good.
The unique option that I think was extremely good was the automatic sound calibration. This feature uses a microphone that you setup in the listening area. The system then sends out a series of test tones and then automatically adjusts the unit for the optimum setup given the results of the test.
My only gripe with this system is the FM antenna. It has horrible reception no matter what I do. It does not use a standard dipole and just does not bring stations in clearly. I would say it's the area where I am living but my my other three system in the house bring everything in clearly.
If not for the latter, I would give this system a 5 star all around.