One of the first studies to show that lead leached out of crystal was published back about 1988. Since then I've followed the practice of putting liquor into decanters prior to guests' arrival, and back into the bottles after they leave.
The only decanter I no longer use is my WT decanter. Would it be wrong to serve something else in it? Say PVW 15?
As for lead crystal, some manufacturers are moving to titanium, which is not only safer but makes for stronger glasses. One of them, Zwiesel, claims that their glasses are "truly break resistant, practically unscratchable and virtually unstainable"