I originally bought the CS515's cheeper little brother, the CS315, which is exclusive to Currys, and built down to a price for them, and it showed. The sound quality was only average for a £200 system, but there was a constant buzzing noise when playing CD's, I returned the item to Currys, and tested two more in the shop, both these did exactly the same. I then tried the CS515 at £300, there was an instant improvement in overall sound quality, and no buzzing from the CD player.
I was a little reluctant to pay the extra £100, but felt the difference in sound quality was worth it.
The unit itself has a CD player, FM/AM radio, DAB radio, and several inputs for Video, MP3 players etc.
The speakers that come with the CS515 are Onkyo's DN9BX, nice looking maple, 2 way, bookshelf models, What Hi-Fi give them 5 stars, personally, I think 3 would be more accurate. Knowing what I know now, I would have bought the system without the speakers for £225.
I have since bought a pair of Yamaha's at a bargain price, (see my other reviews) and they have made this system sing, and really show how good the CS515 really can be. The speakers are connected to the Hi-Fi via proper, sturdy screw-in connectors. The remote control works well, even when it is pointed nowhere near the unit.
There is a 'Super Bass' button, which really does rattle the windows, and you also have the usual bass & treble controls. The CS515 also has a 'Direct' button, this by-passes the bass & treble controls, giving a more accurate reproduction, although personally, i prefer the treble up 2 points, and bass up one point.
The CD player & DAB radio are very impressive for such a small (shoebox size), and relatively inexpensive unit, the FM radio is very good, but overshadowed by the DAB.
I also have a Sandisk Sansa MP3 player plugged into the CS515, via a Sansa Docking Station, By replacing the 3.5mm to two phono's cable that came with the dock with a better quality one, the sound quality is very close to CD quality.
A friend of mine paid more than this for a Bose wave radio/CD, and he regretted every penny after hearing the Onkyo, Ok the Bose is impressive for it's size, but as far as true sound quality goes, there is no comparison.
Overall, this is a good looking, compact hifi, with good features, and an excellent sound if paired with decent speakers.