on my 1Ghz TiBook, 512MB RAM doing an archive and install, no additional language packs, it took less than 45 minutes.
the only 2 little tiny glitches was i needed to upgrade Toast to 5.2 (i had 5.1) and i needed to specifiy which version of Stuffit to unstuff files (for whatever reason i had 2 versions on the machine)
so far its just freakin great. fontbook rocks. expose is SO fast and beautiful its just a marvel to see it happen. i really like teh slightly subdued look + feel. so far it defintely feels much snappyer, i am hesitant to say its "faster" yet - lemme use it for a week.