Leaving at 5 stars as for owners of 600's or lower, this will likely meet your needs perfectly so ignore what's written below.
My Drop 6XX (based off the 650) cable died on me and I've been looking for a replacement cable. The 650 cable on Sennheiser's website is out of stock so I decided to try this one as it was recommended to me. After plugging it in I immediately noticed a drop in audio fidelity. You lose a TON of the low end with this cable and it makes all of my audio sound much brighter and less balanced overall.
Does it work in a pinch? Yes. Do I suggest it? Not at all.