My father had thick black hair before he went white, and my brother has thick brown hair. Both have no trouble growing facial hair. So I have hope. Because I'm two and a half years on T, and I'm still working on getting good facial hair. But then, I'm blond, and my hair is fine. I mean, my hair has gotten darker and slightly coarser in the last couple of years (due to T? age? not sure), but I've had superfine blond hair all my life.
On the other hand, I got killer sideburns after only a few months.