The family Lumia Nokia has some of the flagships of the Finnish company that is committed to Windows Phone 7 operating system.
In the comparison that you have in the video that heads this post you can see the iPhone 4S, Apple's latest handset, compared to Nokia Lumia 900. A priori, the difference between the two terminals are evident: a screen much larger for the Nokia (4.3 inches versus the 3.5 of the iPhone) and an operating system that is slowly gaining strength among users and whose interface brings something totally different to what we are accustomed.
The comparison is centered on web pages load from the terminal, access the camera from the lock screen, and the homescreen of each operating system.
What you seem to have an iPhone with the screen size of 900 Lumia? In my opinion I see excessive for the size of the hand, I think the reasonable limit of comfort and usability could be within 4 inches.
Source: iPhone Italy