At $900 you have a 17" (1600x900) quad-core intel with Ati HD6650http://www.newegg.com/Product/Product.aspx?Item=N82E16834215267
Or at $700 you still have 17" (1600x900) Ati HD6650 and you have only i5http://www.newegg.com/Product/Product.aspx?Item=N82E16834215245
Below 17" this you have only the small 1366x768 resolution and 11"-16" screen size.
A nice one at 700$ is http://www.newegg.com/Product/Product.aspx?Item=N82E16834152277
It has a fast HDD, powerful video card and one USB3 port into a small size and medium weight laptop.
Maybe you can ask the following questions:
1. Do you want a desktop replacement or a light traveling notebook?
A desktop replacement can be heavy, with a big screen and powerful components.
A light notebook is light, smaller screen and weaker components.
2. What is the maximum amount of money that you can spend?
Because you asked for a $600 laptop and you also added the $900 Alienware M11x laptop.
3. Do you want USB3/HMDI/eSATA/PCMCIA or other special port?