To the OP: I don't know about And So To Bed (it's a blend I don't like, therefore I never cellared it), but Pembroke flavor changes very little with age. I think it's the cognac topping that may have preserving properties that prevent the tobacco from aging like in other blends. The few changes I notice concern the latakia, which becomes stronger. In other words: when fresh, the cognac is the dominant flavor (to me, at least), but with age the latakia flavor rises to the same level, or maybe even above, of that of the cognac. Note that the cognac doesn't subside, or diminish, with age, it's the latakia that rises. The aroma in the bag, however, becomes fantastic (unfortunately, it doesn't carry to the actual smoking experience). I quite like it both ways. The difference is not huge, but if you want to experience it for yourself, I would say to wait 6 or 7 years, I think there's minimal change after that. Botton line: if you like Pembroke for the cognac, fresh is best; if you wish to enhance the latakia, age it.
