Amorelli uses old briar too.
Savinelli "brags" about using 3 year aged briar in their punto pipes, so the rest ain't ten years old, that's for sure.
Briar blocks change over time, they oxydize and the lignin crystallizes or something.... fresh briar tastes a little... fresh. It doesn't usually taste bad. But it's slightly less stable dimensionally than older wood, and I don't think it smokes as good as it would with more age on it. Mimmo suggests sitting on his product for 2 years, that's the steep part of the aging curve. And I tend to agree, most of the positive changes we see do occur pretty early on. I have 10 year old and old briar in my shop and it's generally harder to work with, stains with less contrast. It usually blasts well, and it tastes good, slightly corky and sweet, very small break in time.
I shoot to make pipes out of briar that is between 3 and 10 years old most of the time. And I have heard no real huge difference from customers buying a pipe from a 10 year aged block and a 3 year aged block. And it often happens I have a guy buy two pipes at the same time, and the source wood may not be the same..... I track this pretty steadily.