The point that
@Channan brings up regarding the larger iPads has a scientific explanation, and it's called
Torque.
I've already discussed this in great detail in another thread so I'm just going to link them:
The problem with the "go to the gym crowd" is that they are ignoring how the iPad is traditionally used - hand held. If you are using it when resting on a table or lap then of course the weight has a minimal effect. Carrying it in a bag or any position where it is perpendicular to the ground is also not going to be an issue.
The problem is when you are
holding it with one hand. When holding it at one corner and using the other hand to touch the screen, the distance of the center of gravity to the axis of rotation is going to be more, especially if you're holding it in portrait mode. It's not just a matter of the mass of the device, the size of the device also matters, because the center of gravity is going to be further away from your hand.
As a very simple illustration, if a device has a diagonal twice as long, and is twice as heavy, the resultant increase in torque (when holding it in portrait) is going to be
quadruple. i.e. 4 times more difficult to hold.
If you're
still not convinced, try taking a MacBook (or any laptop), open it up while standing, hold it on one corner and type on it. Do that for half an hour (while holding it all the while with one hand on the corner) and tell me that it's not incredibly uncomfortable.
The fact that the typical laptop is a clamshell device actually increases the COG distance by a third dimension, magnifying the torque even more.
Rant aside, the nice thing about the 10.5" is that because the overall physical dimensions haven't changed too much while having a larger screen, the torque increase due to larger area is generally minimal.