Even my Philips SHP9500 has stronger build quality than my Sennheiser 4xx, HD558, and HD580. And HD580 is similar to HD600, so the same applies. And I can pretty much guarantee something on an AKG 701 will break before it will on the SHP9500. (Such as those plastic slider pieces the inside of the headband moves on.)
Similar applies to Beyers. They simply feel more durable. I may not have to baby my Sennheisers, but they make me feel like I do.
No detachable cable on Beyers, but that's not all that bad considering the connectors that come on the HD580/HD600 cable. The Beyer cable also has more support at the plug jack. In comparison, the Senn cable is like it's made for a portable headphone.
Honestly, having owned HD 580 for many years, and K701 for even longer, I never had a single issue with durability. By contrast I've read/heard many reports of T5p cable and plug failures, I've seen many "lesser" Beyers fall apart over the years, and my T70s died within 3 weeks of light use. Sure, the Beyers look all big and masculine and have metal parts, and the Sennheisers and AKGs are "just plastic" - but those "just plastic" headphones, IME, just work.