我该选哪部笔电?

我想购买一架笔电
预算是在3500以内这样
这3架，哪架比较好用（整体来说拉）

以下是这3架的Spec

Lenovo Y510P

Processor
    4th generation Intel® Core™ i7-4700QM (2.4GHz up to 3.4GHz, 6MB L3 Cache)
Operating System
    Windows 8
Display Type
    15.6" FHD WLED
System Graphics
    Nvidia GT750M 2GB DDR5 Graphic
RAM
    8 GB (1x8192) RAM
Hard Drive
    1TB HDD
Price :RM3399

Asus K551LB

Processor
    4th generation Intel® Core™ i7-4500U(up to 3.4GHz, 4MB Cache)
Operating System
    Windows 8
Display Type
    15.6" HD(1366*768) LED Blacklit
System Graphics
    Nvidia GT740M 2GB DDR3  VRAMGraphic
RAM
     GB DDR3 RAM
Hard Drive
    1TB SATA HDD
Price:RM3030 (因为原本是4gb的 ,upgrade去8gb 加 130)

Dell Inspiron 15 7000

Processor
    4th Generation Intel® Core™ i7-4500U processor (4M Cache, up to 3.0 GHz)
Operating System
    Windows 8.1 Single Language (64Bit) English
Display Type
   15.6 inch LED Backlit Touch Display with Truelife and FHD resolution (1920 x 1080)
System Graphics
   NVIDIA® GeForce® GT 750M 2GB DDR5
RAM
    8GB Dual Channel DDR3L 1600MHz (4GBx2)
Hard Drive
    1TB 5400RPM SATA Hard Drive
Price: RM3599



这3架，如果论机身热度阿，散热阿，lag阿，warranty方面阿
可以说说看哪个会比较好吗??
抱歉小弟新手， 电脑白痴一名。