Man, I wish these would go on a good sale soon, I've had my eye on them since they launched!
They meet all the criteria I'm looking for in a pair of headphones: stock FR that's easily EQ-able, low distortion in the lower end for being a DD (one of the lowest I've seen regardless of price), better materials and build quality than the HD560S, less than 300g in weight, apparently the most comfortable alongside the HD800S, and backed by a reputable brand like Sennheiser (so they’re presumed to be very durable and I know there won’t be a lack of official or third-party accessories in the future).
If only they cost around $250...