I couldn't say where typing in luks passwords counts. My laptop on which I don't currently use any encryption, and it's equipped with a 2008 Atom chip gives me:
Startup finished in 11.267s (kernel) + 15.697s (userspace) = 26.965s
graphical.target reached after 15.687s in userspace

My server which is also running a 2008 chip, but it's a pentium-D that support 64 bit code takes:
Startup finished in 3.127s (kernel) + 27.333s (userspace) = 30.460s
graphical.target reached after 24.844s in userspace

Maybe because I only encrypt my home directory, it's not counted as kernel time. I do watch the drive lights and start typing in my password within at least a couple of seconds of the prompt appearing, but I guess encyrption does take some extra seconds. I'm using a 7200rpm disc there, while my laptop boots from a fast-ish for these things SD card, which might count for the sort of short random-looking loads that booting an OS involves.