Headphone.com described them as "closed 'phones that compare to the best open models", but I think they are "closed" in name only. They do not offer one iota more isolation than the completely open K701s!
When it gets noisy in my apartment (upstairs neighbor having friends over, yard crew running machines, kids playing in the hall, etc., etc.), I find myself thinking of giving up the D5000s and going back to my DT770s. The isolation may more than compensate for the difference in sound quality.
If there are headphones out there that actually do live up to the description of "closed 'phones that compare to the best open models" (meaning really closed, not just nominally!), then I want them. If they are in the $1000+ range, however, that puts them out of my league!