Has anybody used the D'addario Chromies? They're ribbon wound, and feel like a flatwound, but I haven't been able to hear them. They are very expensive, and I'm afraid to waste my money. The ghs Boomers I use now are just fine, but I'm always willing to inprove. The salesman is so excited about the Chromies that he's offering the first set at 1/2 price. Deal or Gimmick?