IMO, while Virginias may see the most change in aging, "some" Virginias do not age well. Don't get me wrong, I have had some Virginias that rocked the aging process; however, some lose their sweetness, and less sweet ones can become like smoking dirt. Esoterica Tilbury was one that I didn't like aged. I picked up a couple of tins that were in the back of the of storeroom the Briary. One was about five years old, and the other was way older, but he didn't know the exact age. They kept their seal and had not ever seen any significant swings in temperature. Any traces of sweetness had left the Virginias, and the burley had aged to make the rest taste like dirt, leaving the whole mix tasting like you had just crumpled up some leaves, sticks, and dirt from the floor of the woods and tried to smoke them, Blech! A fresh tin of Tilbury, renewed my faith in this blend, giving me a whole new perspective on it. I just don't recommend aging that one.
There are a couple of other aged blends that I don't recommend aging as opposed to just enjoying a fresh tin, McConnell's Oriental, MacBarrens Mixture (Scottish), and their Matured Virginia, seem to all get dirty tasting with a significant loss in sweetness.
I am guessing that it is the burley mixed in and the type of stoved Virginia used. And, I am curious as to whether age will do Mac Barren's Old Dark Fired any good, as it is the same sort of blend as Tilbury. And, Per Jensen had mentioned that the blend wasn't produced with any intention of aging, as aging tobacco on purpose (to him) was more of an American trend.