I recieved my 3ohm replacement tank cartos and finally got around to trying one. They arrived in plastic along with a 1.5 direct replacement. I ohmed them out on a meter and filed 3 small notches on the edge of the flanges of the 3ohm ones to tell them apart (had I gotten 2ohm ones, I would have put 2 notches).
Anyway, I'm happy to report that (just as folks had expected) the 3ohm fires fine in my PT and in the gold-button manual, both of which did not fire the 1.5ohm dual coil. The draw is better, and the flavor IMHO is better too... at least on the pure VG unmentionable juice I'm running in it right now.