Of course you can see the 530'er Shure not compare with the Sennheiser - ultimately cost the 530'er approximately 10x longer (around 350 euros). Thus, I also knew that I have to make certain compromises. However, I would like the CX 300 II not buy me one more time.
On the one hand my earphones are too small. Everyone needs to decide for themselves, but for me personally the little buttons are down to tiny. I feel like I have something in the ear and the listener sit well accordingly. The CX 300 II but are actually held only by the Earadapter and struck me quickly out of the ears or postponed. This means that you often have to readjust the receiver (if one moves a lot - while sitting on the couch, this is of course no problem!)
Another Apsekt could not convince me is the bass. He is far too blurred and not precise enough. He covers the otherwise good quality medium and high tones what the listening experience tarnishes painful.
Why I give only 3 stars? Because me the quality has subjectively unconvinced. Then why not 1 or 2 stars? Because I anrechne that you can not expect too much for 35 euros.
However, my recommendation: Investments prefer still a bissel more - the difference can hear and worth of each. Shure is also very good priswertere alternatives (than the 530'er) and Ultimate Ears or Klipsch offer listeners that you no longer want to give it!
At the listeners you should not save - what one buys an MP3 player for several hundred euros when you save to the listeners? Then I can stay with my mobile phone and the enclosed headphones ...