Let me put it this way. Jolla 1 has a 4.5" screen and (by today's standards) large bezels. It is about 5.75" edge to edge and it is just about the top of what I would call "comfortably usable". Please note the word "comfortably". I know I could use a bigger one, maybe even fit it in a pocket. But it would not, by any stretch of imagination, be "comfortable". Xperia X has a 5" screen but smaller bezels that Jolla 1, making the entire device "only" 6" edge to edge. And that is above the comfortable zone, which is why I do not use it, even though I have one and it is superior to Jolla 1 in every other aspect. The lack of comfortable use is the deciding factor.