My first response to this was "Well, duh..." Everything takes longer in older bodies.
It's true that at 63, it's taking me a lot longer than younger guys for hormones to do their thing -- hair growth is a lot slower than I'd like, and it's pretty hard for me to put on muscle. On the other hand, my voice has dropped nicely, I'm a lot stronger than I've ever been, and I'm now read as male 100% of the time. The one change that's happening fast is that I'm starting to go bald -- but, oh well, I know it helps me pass.

And, yeah, I worry about surgery -- I know I heal more slowly now. So, top surgery for sure, but right now the complications of bottom surgery seem a bit too risky. And I have to worry more about high cholesterol, heart disease, and whatnot, and maybe I'll die younger. No one knows when they'll die, and who'd want to?
But guess what, kids, life isn't risk-free no matter what, and when you consider the alternatives to transitioning -- I'd probably be dead right now.
I could die in two weeks on the solo canoe trip I'm taking, or on the drive to get there (the latter is more likely, statistically). So I should stay home and look at my four walls? Don't think so...