I am one of the ones that have taken advantage of the Koss warranty...I had a set of their old IR Kordless models and a set of the Pro-4x/Plus models that I sent in this past spring....
I got back a set of the Pro 4AA/Titaniums and a set of the 900MHz JR-170's....
I also have a set of Grado SR-80's...and have had the 325i's....
I really like the sound and convenience of the JR-170's, but I don't much care for the sound from the Titaniums...compared to the 170's or the Grados they seem to be muffled, rolled off in the high end, not as transparent, nor as articulate as my other 'phones...but they do isolate sound better so I use them and a long extension cord when I'm vacuuming the floor...I've got a REAL noisy vacuum cleaner...
Just my $.02...
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