I am using this laptop since two years daily for 10 to 12 hours. It is a good heavy duty laptop. It is not getting getting heated much as compared to other laptops.
I also have a dell inpiron 1525 laptop which is no compare to this lenovo product as thinkpad laptop is far better quality and so is its price. In both the inspiron and think pad laptops I see huge difference between the heat generated, battery durability, quality of parts like hard disk, dvd drives and other components.
Problem is it is a bit heavy but that is fine and important as compared to its newer sleek version of t440s.USB ports are less. Also the keyboard is uncomfortable due to some of the important keys placed at the top of keyboard, but once you get used to it it is ok.
The service of lenovo is good as compared to fooling service of dell.