I pulled out a very old Dr. Grabow and smoked a bowl of Telegraph Hill. It smoked well. I had tried the Grawbow without a filter and it smoked lousy, so tried it tonight with the filter and it was first rate. I'm not a filter guy but this pipe demands one. It's a very old Grand Duke that I've had since the late 70's or early 80's. I was pleasantly surprised.
Hot shot: a Duke and a Royal duke are my lunch pipes! Love them, and the timing in the little bowls is just right. (As are my Kaywoodies and my Piccadilli pocket pipe).