I'm on a MBP 13", C2D 2,4 Ghz, 128 gb SSD. I noticed improved boot time between SL and Lion, and since the latest DP2 update I went from ~22 sec boot to ~17 sec. Seems like this is something the boys in Cupertino takes seriously, and I like it! I clock the time from pushing the power button until the OS is loaded and wifi has connected. How big of a difference is you guys noticing, if any?