Hi! From my point of view P151SM suits my needs better than P150SM or P157SM, because is cheaper and right now I don't need a powerful MXM graphics. The only issue I have with this model would be related with the missing backlit keyboard. Would be possible to swap the non lit original keyboard and install an illuminated keyboard from the P150SM model? Also, as a last question, I see the powerbrick for P151SM can provide up to 120W. Is this swapable with the one from P150SM which should provide 180W? Thanks!