Don't know anything about the Plantronics, but I can tell you that I bought my Telex 5x5 Pro III when I got hired in '96 from Shirley Meyers...she's the vendor in the Memphis area (I can get you her number if you want it. There should be some flyers around the crew lounge bb's) She did the custom ear pieces too. I absolutely love it and have had no problems with it whatsoever, other than leaving it in the a/c a couple times. Great piece of gear.