Smartphones is probably a device where you, if in doubt, should probably buy a slightly larger phone than you might initialy find comfortable just because your perspective tends to change after you have used it for a while. Atleast if you are upgrading from a smaller phone. After a year of using the 920, it has gone from being the huge phone to the minimum size I would consider. The same tends to go for TVs as that "huge" TV begins to feel perfectly fine after a while.
This is the reason by the way for me looking at the 1520 as my next phone rather than a slightly larger sucessor to the 920. Some things I do could really benifit from the bigger screen.