Pros:I like the fold-up concept; they fit nicely in my briefcase.
Cons:This slow degradation weakened the wire (about 14-18 months)and now is out of warranty.
My HP-550 is dead in one ear. It took some time to troubleshoot the problem. I isolated it to a pinched wire that must be frayed inside the insulation. The left earpiece fold-up pinched the left wire, which feeds the right earpiece.