dude, every 650m has overheating problem, but nvidia did'nt made the 650m for gaming, they have that GTX series for that, 650m, 7730m are just multimedia graphics performers, which we use for gaming..

and gaming laptops, though expensive, can handle this heat, as they are designed for it, the good placement of internal components and material used is absolutely necessary, but both DELL and sammy are'nt designed for torture temps of 90-100 everyday for ~6hrs., occasionally it's OK, but you are extreme gamer, i recommend you DELL just because my dell has reached max of 85c on GTA4 4-5 hrs gameplay, (90c on f1 2012, but that's because it was using intel gpu), sammy reaches 90c constantly, and seeing your gaming needs, it would be a stress test for that poor lappy..
Rest is your choice..