The design of this earphone is amazing! The design is actually part of a series of earphone designed in collaboration between BMW DesignWorks Singapore Studio and Sennheiser. Naturally, Sennheiser provides the drivers and sound, while BMW the design.
These pair of earphones look really sweet and will definitely catch people's attention. It is lighter and more plasticky than the commercial photos. The 'chrome finishing' on the earphone is just painted plastic, but it is needed to keep the earphone lightweight. The only real chrome part is at the cable splitter.
In conclusion, these earphones won't disappoint with the practical yet beautiful looks. It's minimalistic but at the same time stands above the crowd, just like an Apple product.
These phones are worth exactly their value, and are mid range earphones, good enough for the general consumer, unless you're a golden ear audiophile (which I'm not).
Although the balance and separation isn't as good as the original Klipsch S4, overall bass response is a lot better, fuller and has a heavier thump than the S4. Generally, I feel the highs, vocals and bass are more emphasized and possibly better than the S4, although the bass is slightly muddier but not too noticeable. Also, the mids and lows are not as well brought out as the S4, although it's there.
The sound preference will really differ from person to person, but generally I feel the sound signature is really warm, with instruments well brought out. The sound is also generally balanced with bass response being just right for my tastes. I would put it on par or even better than the Beats Tours (lol)
Sennheiser being Sennheiser, will definitely design lasting and durable products. They design more for practicality than the general feel of the product, unlike their competitors, like Klipsch.
The Klipsch S4, and possibly even S4 II will not last very long due to their weak cable housing and poorly designed connectors (usually stress points). But the CX870 feels really durable, and the connectors feel strong and supple. You can definitely put these in your pocket without fear of stressing the cables.
Although the earphones seem quite large, they are actually really lightweight. But sometimes, they might just loosen with a little walking. I fix that by fitting the earfins from my CX680 (totally adaptable and is a perfect fit).
Overall score: 9/10
In conclusion, an earphone good enough to last and for everyday on the road use. Great sound, affordability, quality, design and durability. The only company able to pull this off is Sennheiser. Buy it without hesitation.