Hawke:
Conventional wisdom -- which I generally accept here -- is that three years is the minimum needed for a blend to really start to show some development. To me, six months is "fresh." (I recently was able to compare a new tin of a blend with a six-year-old version I smoked last year. It was like smoking two different blends: One "very good" and one "absolutely amazing.")
If you only smoke aromatics, aging will have very little, if any, effect. But if you enjoy non-aromatics, then you can expect to see significant changes with time. How much a blend changes depends on the blend, the "vintage" (since we're talking about an agricultural product that changes from season to season, year to year), and how well it's stored.
I've had blends that I thought had peaked after four years or so, due to the delicacy of some of the leaf. And I've had blends that were 10-30 years old that I thought I could have saved for another 10-20 years.
Why not mention some of the blends that you know "fresh." If I don't have an aged sample to send you for comparison, it's possible others here might. (I definitely get the "patience" thing!)
Bob