This is interesting. Enlarging being a generally solitary pursuit, you tend to arrive at your habits and preferences in a vacuum and sometimes you wonder how your own techniques match those of others who are working away in their own darkrooms. I especially relate to the comments on manipulation. In that 15-25 second range, my burns and dodges feel smooth and natural, at 60 secs they feel clumsy and unsure, I have to count along with my audible to know how much of a burn I'm giving and can hopefully repeat it.