I upgraded my Thinkpad to Ubuntu 9.04 (Jaunty Jackalope) recently. My laptop has a solid-state drive and I had tweaked the boot process previously so it was down to 15 seconds. I had heard that Jaunty had drastically decrease the boot time, but I figured my computer could not boot much faster than it already had since I had modified the boot process drastically.
I was wrong. The first time I rebooted I was amazed at the speed of the boot. My boot logger recorded the boot as taking 8 seconds. I have rebooted once more since I installed Jaunty and that boot only took 7 seconds.
The main reason the boot time is so fast is due to my solid state drive. That is how I got my boot down to 15 seconds before. However, 7 seconds is a ridiculously fast boot time in my opinion. Especially since it seems like it takes only about 3 seconds until my login manager is loaded and waiting for me.