Update:

-The ferry to HKIA was quite efficient, and the VAT refund process was as simple as advertised. My only beef with it was their insistence on taking the 845a boat for my noon flight; that seemed like excessive schedule padding to me.

-This afternoon, I ended up taking one of the mini-vans between HKIA and Shenzhen Bay, and learned that this -- or any private car -- is a really dumb way to play things on Fridays, especially if you have e-Channel. The border crossing took four times as long as it did for me last Friday on foot. I know we all hate standing in lines, but if the choice is standing for 20 minutes or sitting in idly in a car for 80 minutes, the former wins out.

-I actually would have taken the ferry instead, but the ticketing and boarding seemed to be pre-immigration/customs, but I had a checked bag (need to go through immigration to get it, I think). Surely they've cracked this problem, but I wasn't willing to wait in the ticket line in order to figure it out.