Well, I ran Onyx last night, restarted the computer, shut it down, and went to bed. I just woke up and turned it on, timed it, and it took about 32s from pressing the ON button, to seeing my background, and a total 1 minute, 18s to being able to open a Finder window and open up a folder.
Sure, there were still things loading (I have quite a lot of stuff opening at startup), but I consider being able to maneuver through the file system a "Usable State." And considering any of my Windows machines take at least 2-3 before I can do anything, this is pretty fast. Although, the BIOS of my Windows/Linux box s a lot slower booting, so it's not a good comparison.