Thanks for the responses. I guess it's a case of waiting and seeing what my next blood test reveals and what insight my endo has. But shrinking balls is a good sign - not just as an indicator that the HRT is really taking effect physically, but also that it's one more check mark I can put in the mental "yup, you're really trans" column: the loss of those once-prominent signs of manhood is something I'm rather excited about, and it's not made me think for even one second, "My god, you're insane. Stop it right now!"