Lenovo y510 or alienware m14

Neither would be my first choice, but the Alienware 14 just seems better. The 765m offers most of the performance of 750m SLI without the headaches, the Alienware has a decent 1080p IPS screen, superior warranty and sturdiness, manual GPU switching, etc. If you can get a good discount on the 14, consider it.

The Clevo w230st and Clevo/MSI 15-inch "gaming laptops" offer more bang-for-the-buck than both.
 
What do you mean?

The machine should not overheat unless you block the intake vents on the bottom. I find that GPU cooling is good and CPU cooling is average. After a repaste, temperatures should be much better than those of other laptops with similar hardware.