I haven’t used them long enough (only about 2-3 years I guess) to be able to tell you anything useful, either.
From what I read, copulin content and intensity will vary not only from woman to woman, but month to month. The most appealing ones according to the studies are those of very young women (teens I believe) who are ovulating. Ilsa posted a pretty in-depth (and inspiring, haha) article on the subject of cops:
I can’t tell you anything from personal experience, but it seems to me that as we age we benefit more from additional pheromones - we know that most of us produce decreasing amounts of some hormones with age and I’d speculate we produce fewer pheromones too.