Thanks for your comments guys!
Now I tried some heavy testrenders both in Vue and Bryce; I have to say that it doesn't feel fast at all; these monster progs eat up my Centrinos for breakfast lol...I don't know how many proc. you should have in order to "feel" the  shorter render speed but the stability of the software/hardware is excellent! (Beware of the  overheating P4  proc. in laptops - go ONLY for Centrino! )