I used Sony xperia z ultra 6.4 inch screen.. Samsung mega 6.3.. 6.3 inch screen.. Actually to me as long is minimum 5.5 inch the phone and screen is just nice for my hand. Max I go for screen now is 6inch..else not easy to use n put in pocket.
What all the fears that is coming from mobile users regarding
the useability of the 6"; 6.3" or the 6.4" screen size are
a waste of time. Think about it, why let your mind controls
your life that your hands cannot hold it and what not.
This range of sizes are known as phablet and the the smallest
tablet is at least 7" screen size.
The future will be the smartest phablet with powerful
processor combine with longer battery life, 4GB Ram
with internal memory of at least 64GB and can add a micro
sim of at least 256GB.
As the phablet gets more powerful, it will get more
popular and mobile users will not think of it as a phone
anymore but as a phablet with a phone. Carrying a full
size laptop will be an issue when the phablet can do the
job just as well.
So complaining that the phablet is too big for your hands is
just a matter of your mindset. Just use it as a phablet with
a phone and you don't have to carry it in your trouser
pocket anyway. There will be many innovative ways to
carry your devices around when the time comes.