Wrong.
http/www.notebookcheck.net/NVIDIA-GeForce-GT-750M.90245.0.html
The y510p laptop is still better. in terms of CPU and GPU performance.
As the link above shows the 750M with GDDR5 eats the 660M. The y510p is the version with GDDR5.
Also the CPU in the y510p is Haswell architecture, and the other is Ivy Bridge. Haswell is more energy efficient, rated for a higher clock speed, performs better even at the same clock speed and as expected is all around better.
The cheapest y510p and the laptop on Amazon have the same screen resolution, but the y510p has 2GB more RAM, 250GB more HDD space, and a 1 year warranty.
Best to go ahead and pay the $90 more that the y510p costs over the other one, since it brings small boosts to virtually all aspects of the system except the display.
Also if you want even more performance for cheaper, you could also consider the y410p which is a 14" y510p but otherwise its all the same.