First part of my MacBook Pro upgrade is finished:

Mac OS Lion system boot before SSD: average of 45 seconds.
Mac OS Lion system boot with SSD: average of 15 seconds!

Overall all Apps start much faster and the new performance is pure fun.
I am looking forward to see, if the 16 GB ram (instead of 4 GB now) will reduce the boot time a little more, at least working with big pictures and movies should speed up.