When looking for a laptop, you have many choices in size. Dell is now selling a 12″ screen unit. Macbooks have their 13″ screen. 15″ is average screen size. The 17″ Macbook Pro’s are hot. You can even get a 20″ screen from Dell. Each of these laptops have their advantages. It all comes down to speed and portability.
The bigger the machine, the heavier and harder it is to carry. The smaller the machine, the slower it is.
If you are using a laptop as your main computer, speed should be a factor. If you are mobile quite a bit, then size should be the factor. I am personally using two different laptops as secondary machines to my Desktops.
The first is a Dell Latitude D810, with 15″ screen. This is huge and heavy. I do not enjoy carrying it around with me. The second is my Macbook w/13″ screen. The machine is still fast (but not a Macbook Pro speed), and is light and easy to carry.
I personally prefer smaller laptops. I do not use these as main computers. I like to carry them with me where ever I go. What do you prefer?