From the common 15.6 to the handy 11 inch size, what differs in productivity for a Laptop?

This question has kept hitting my mind on and off ever since laptops came into my life. Today, as I've successfully ventured back and forth through 3 laptops [Dell (15.6 inch)-> Sony Vaio (14inch, RIP) -> Dell(15.6 again!)], let me jot down the observations I've seen with reference to screen sizes of Laptops, Tablets, & now the new Laptabs 😨

15.6 Inch:
Pros:
1. Conventionally used by everyone due to its full size keyboard with a number pad (unlike the 14 inch versions).
2. Screen size is great if you want work done faster.

Cons:
1. Not at all handy.
2. Feels like a slab held in your hand.

14 Inch:
Pros:
1. Makes sense to a daily user.
2. Screen size is apt for most of the mundane tasks, but can get clustered if you want to work on spreadsheets or design something.

Cons:
1. First con I found NOW (while hunting for a new laptop over the past 2 weeks) is that now-a-days 14 inch laptops (checked on a nominally high budget of Rs 45K - Rs50K INR) don't come with a dedicated graphics card (such as Nvidia or ATI Radeon) option. - but why???????????????????????????????????????????????? [My Vaio used to have one - too bad they shut down production!]
2. People don't prefer 14 inch laptops was the answer that I got from salespeople.

Other Observations:-
1. Laptops don't seem to have gotten more robust, but they've definitely gotten stronger (at-least as per reviews and observation) than some Sony Vaio models and Toshiba models with hinge issues just 2 to 3 years ago.

2. Color options and variety of materials used to add texture to the lid or more grip to the body is a welcome gesture. But I feel that customization of laptops still was much more fun and lively with Sony Vaio.

Now to Conclude with a Question:
Inspite of all these, people still prefer 15.6 inch (I'm talking about the Mango people here, and not the Apple lovers). Why? What do you think it will take for people to change the trend of 15.6 being a standard to preferring a 14 inch as a standard.

As a user of both 15.6 and 14 inch variants, and brief user of 13.3 inch variant, I'd still prefer a 14 inch laptop over to any other size.

What does CEans have to say about this? Do add about your observations with 2 in 1 PCs (Tablet + PC) if you have any!

Do hit the polls as well!