On a phablet the size of the screen isn't a con. Granted though, that the 1520 is big. Very big. There's too much bezel going on, which makes it too big for many pockets. Hell, most Windows Phones are too big for what they are. Only the 925 makes the cut, other than that, they're all too thick, too wide or both. Beautiful, yes, but bulky too.
The problem with all this screen size debate is that big screen phones (mostly high-ends) are good for some people, but others, who like smaller screens on high-end specs are left in the dark. Even the "mini" versions are starting to come out with 4.5'' screens (HTC One m8 mini). I, for one, simply refuse to use a phone with two hands. I've even considered leaving WP one or two times simply because, while I have a phone with a decent screen size and specs (Lumia 820), I don't have a 4x3 keyboard with t9 so I could type with just one hand. I always end up grabbing the phone with my two hands and that never was practical for me when I'm walking. That being said with a phone the size of the 1520, even the big screen fans can say it's too big. But it's not the screen's fault in this case.