Penzance tastes like, well, Penzance. And surprisingly like the new Balkan Sobranie made by the same good folks at Esoterica. As fnord pointed out, ASTB is also very similar. Seattle Pipe Club Plum Pudding comes close, but lacks that slightly floral, herbal tinge. SG Balkan Flake has some of that, but it lacks the other flavors that come from the Orientals, since it only contains VA and Latakia.
I find Penzance to be a very delicate treat. Once I had smoked 3 bowls of it in 3 different well rested briars over a course of the day, and not too long ago I smoked 3 bowls pretty much back to back in the same Group 3 Shell Prince. Halfway through the third bowl on both occassions the "magic" was gone.