You need to check benchmarks online and decide if the improvement in fps is worth the replacement of the GPU. I am not sure if PCS is offering either the GTX 770m or GTX 780m as upgrade options yet.
Yeah the graphics on the games I play are amazing. But I was just concerned if it was powerful enough to handle the next gen games that are due to come out like GTA5, unreal engine and the new battlefield on high settings.