I have noticed many of these differences but never thought to comment on it here. I have especially noticed the longer inhalation at the heart and the short exhalation between lower dantien and bladder point. I find it unsettling to change the rhythm of my breathing in and out to any great extent and settle for beginning to breath out towards the end of the long heart inhalation, otherwise I might take off like a helium balloon. I can't believe that you have to be breathing in for every second of Master Lin's sounds -presumably it has an effect anyway and I notice that I value feeling more generally relaxed about the process rather than getting it 'absolutely right'.
Incidentally, I found part of the previous post particularly useful when it dealt with what to do if you lost your place in the sequence. I had previously taken this as a sort of 'failure' but I like the reframe of seeing it as going deeper into the emptiness. It is also interesting that I often end up finishing with the tape in these circumstances. The old unconscious mind seems to be keeping an eye on things!!
Love
Kev