Having had the very excellent opportunity to see this story take shape, my comments might be a bit biased. And I happen to agree with Elf about spoilers, so it's hard to squee about anything in particular without giving things away.
You managed to find the perfect occupation for your Snape, I think, and I really loved what time and distance and comfortable living helped him to become. And your Harry broke my heart---I felt his pain, shared it. As always, you've given us something unique and wonderful.
In fact, I have so much love for this story, I'm gonna read it again. And probably again...
You've made me want to read Captain's Courageous, as well. Just not tonight... *makes note to self*