I bought this one because it was so cheap and on the off chance I wouldn't have to upgrade..
I think some people are being a bit generous on the sound quality- I would hardly go as far as 'amazing' or 'sensational' however it is not that bad at all.
A few problems I found were that it is appalling quality when my engine is turned off, and the jack plug in is not the best quality (obviously) and so hence needs to be put in in an exact position.
Overall, the noise is good when the engine is on and so it serves a purpose for bombing it down the motorways.. Would recommend it for the price!!