It's not so much about having the most portable one. It's more about having the best one that is still portable
The 15" comes in three models, but I'm not a very techy kinda guy, so maybe someone could explain, in plain English (or Dutch

) what these differences mean?
First:
2.4GHz vs
2.53GHz vs
2.66GHz
Next: Intel Core
i5 vs
i7
And finally: NVIDIA GeForce GT 330M
256 MB vs ditto
512 MB
It needs to run the entire CS5 suite smoothly (but mainly PS and Ai) and preferably be able to run some games (either in a virtual machine, or natively on Steam
[think of games like TF2 and CS:S]).