What do you plan to do with the system? The 630 is better for multitasking since it has four cores, but the i3 is generally faster in single tasks. I'm not quite sure how the i3-m series compare to their desktop cousins. Also, there is the laptop vs desktop thing to consider.
I'm in college and I need it for the basics: typing up papers, research, browsing the web. I also like to play the Sims 3 and other games. I am still in the process of deciding whether I want a laptop or desktop and hoping someone here can help. Also, each computer is about $600.