I really wish I could give this product 5 stars, but some serious design flaws knocked it down to 2 stars. Unfortunately these design flaws exist in the more expensive 558 and 598 models as well.With regards to the cable, Senheiser gets some design elements right, and others wrong. The included cable for the Sennheiser HD 518 headphones are too long for typical uses, and most people will be using a 3.5mm plug size instead of a 1/4" plug size. It is awkward to manage a long cord when it's connected to a tablet or a phone, and the 1/4" to 3.5mm adapter makes the plug stick out 2" from the end of the connected device, making the user experience clunky and awkward for some of the most common used audio listening devices. Thankfully the cable is removable, which is a great feature that extends the shelf life of these headphones because the cable usually wears out before the actual drivers inside of the headphones do. Also, most aftermarket cords come in a native 3.5mm jack size so that you don't have to fumble around with clunky adapters! However, expect to spend another $15 to get a cable that is compatible with this set of headphones. My recommendation is to only buy these headphones (or any other headphones in the 500 series such as the 558 & 598) if you are willing to do an aftermarket cable upgrade. The shorter cable length and native 3.5mm size of the aftermarket cable I bought made this pair of headphones much more convenient to use.However, lets say you want to use the product as is, without shelling out any money on aftermarket parts (because lets face it, a high quality product should work right out of the box without issue). The biggest problem is that the 1/4" to 3.5mm adapter included with the headphones is of hopelessly low quality; the casing of the adapter is a cheap plastic, and the plug is made out of a very malleable metal. After just about a weak of use, I had the headphones plugged into my laptop's aux port while using the included adapter, and the tip of the adapter BROKE inside of my aux port. Given how the 1/4" headphone jack on the end of the cord is large and heavy, I would have expected that Sennheiser would have included an adapter that could either withstand or migitate the forces and torques that the headphone jack would encounter from daily use.The included adapter is also incompatible with many phone cases. Since the diameter of the adapter is relatively large, the adapter would get caught on any phone case that encircled the phone's aux input, preventing me from fully plugging my headphones into the phone. Other 1/4" to 3.5mm adapters such as the Cable Matters 5-Pack, Gold Plated 3.5mm to 6.3 mm (1/4 inch) Male to Female Stereo Adapter worked flawlessly with all of the phone cases I tried out, and were of significantly higher build quality too. Again, another strike against a product that should be 5 rated 5 stars.In terms of positives, the headphones sound amazing and perform well with whatever Metal, Hip Hop, Funk, Rock, and Folk songs that I throw at it. I'm not too much of an audiophile, so other reviews will be more in depth in giving a description of how these headphones sound, but I can certainty tell you that Sennheiser put a lot of effort into making them sound good. The headphones have decent padding, and are extremely comfortable to wear even when I'm wearing glasses. These would be the perfect mid-range headphones for the average person if Sennheiser addressed the ergonomic/usability issues I raised in my review.