For me it really depends on the cigar. Most NCs are great fresh and seem to lose some punch after time, where opus x seem to get better with age. Because CCs arent aged like NCs before neing boxed/shipped i usually dont touch until at least 3 years. I have some from the 50s, 60s, 70s, 80s and on. When it comes to stuff that old it 100% comes down to storage conditions. I have smoked sticks that were 10, 20 years old and were dead flat and some that still had room to age more. Its really tough to experiment with aging when you have a smaller collection (or really expensive if you buy vintage cigars at auction) but It gets much easier when you start building a big collection of boxes and you get to the point where you only smoke a couple sticks from each box per year.