Thank you Lmeow,
so why the i7 720QM is about $200 cheaper than i7 620? is it because the 620 has a 2010 technology and 720 is a 2009?
I'd assume so, and apart from the newer technology it also has an integrated GPU which is useful if you do not need any dedicated graphics power.
Besides, it's Intel - they are selling Core i5 680s for around the same price as a Core i7 870 or 930.