I haven't updated again after HF17/18, but it took a good 24 hours to download the entire block chain a couple months ago.

Also, I assume this /dev/shm setting still applies. I was up to 32G for /dev/shm by the time HF17 rolled around. I was never able to get a complete download at all when I tried to do it without using /dev/shm (which meant I needed to restart with --replay [another 12 hours] after every reboot).