I am fortunate to have a cellar that allows me to pretty much smoke my favorite blends in various stages of aging from fresh to over 15 yrs. I have smoked much "older" blends, dating back to 1948.
I don't generally smoked latakia first type blends. I prefer Oriental centered blends and Virginias with and without Perique. At present, I have an 07 tin of Greg Pease's Mongomery, a similar dated tin of Cairo and a tin of 2004 McClelland Rose of Latakia open. This a pretty representative mix of my favorites in these categories. I don't particularly enjoy Burly centered blends.
I believe any blend can benefit from five years sealed in a tin or mason jar. I think Virginias can age as long as you want and they continue to change, for the better IMHO. VaPers become more PerVa with time. I like this change in the blends of that type I smoke because they don't start out too Perique heavy to my tastes. I enjoy Telegraph Hill as a representative of my VaPer tastes.
In my experience, many blending houses devote less space and time to aging their tobaccos at the phases they control. Understandable as time, and space is money. Couple that with high demand for "hot" blends or brands and you have tobaccos that, in my mind, need to sit.
I like the "mellower" taste and feel of well aged Latakia. It suits my taste. It may change a particular blend to a point a blender did not intend but, so what?
I am old enough to have been smoking a pipe when Dunhill blended tobacco was still fairly readily available. It wasn't still being made but it could be found at prices I could afford. Dunhill aged their tobacco before and after tinning to a point that is probably not seen today, and it showed...to me anyway. This applies to both Virginia and English blends. These blends had a taste that is not the same as today's blends. It was stopped because it was expensive and laws changed in Britain.
I find McClelland blends are the best candidate at present for extended aging. The oxygen depleted environment they tin tobacco in means the changes take place slower than most other brands...to me anyway.
McClelland strives to ship their green,brown and black label blends with two or three years of age after tinning. I applaud this. They are big enough to do this. I have bought GLP blends with dates on or two weeks before the date I purchased them. His blends are generally much anticipated and in high demand. I don't mind one bit doing the aging in my cellar in this case. Time is money and I want GLP to thrive.
Even burly blends can benefit from age. I was fortunate enough to be present when a 1948 key top can of Edgeworth Ready Rubbed was opened at a Columbus show some time ago. It was fantastic.
The bottom line in my experience is buy more than you smoke. Put some away and in five years you will be rewarded. In ten, you will really be rewarded and so on. That being said, if you don't see an improvement with time in the blends you like, don't worry. One thing is for certain though. The blends you enjoy will never be less expensive than they are today.
The REAL bottom line is don't worry one bit about others (myself included) think is "right". Pipe smoking should be a relaxing, enjoyable endevor and if you over think it, I believe it lessens the overall enjoyment.
Relax and enjoy!
Mike S.