Hello,does having more RAM in your Graphics Card make a huge difference in playing the most graphically demanding games(2GB card like Geforce Gt 540M VS 3GB card like Geforce Gt 555M)like Crysis 2 and maybe games to come in the future like Metro 2033 Last Light,Stalker-2 and Future Soldier......assuming that the amount required for Graphics RAM for such games will be on an increase in the future ?
BTW there a minor catch because the NVIDIA GeForce GT 555M does not come with optimus technolgy whereas the NVIDIA GeForce GT 540M comes with optimus.
Now no matter how better or powerful the NVIDIA GeForce GT 555M card may be over the other one but it lacks optimus.
Optimus is when your not playing games or doing other high end graphical stuff then your laptop swithces from the nvidia GPU to the in built intel graphics card thus saving battery and minimising the tempreture of the notebook.
sO I Think i'll go with the xps 15 with Geforce gt 540m card in this regard.