Hey Bimmer Guy,
I spoke to my doctor about this the last time I saw her. She said after my hysto, I'd maintain the same dose for a few months (unless there were obvious issues), and then we'd do blood work and take a look. She said it takes some time for things to settle out and that in her experience, most guys are able to cut their dose down because their levels are naturally a bit higher without the competing estrogen.
I see her again in 3 weeks, so I'd be happy to ask her to explain in greater depth if you'd like.