I did buy this phone http://www.gsmarena.com/sony_xperia_z_ultra-5540.php http://www.gsmarena.com/sony_xperia_z_ultra-5540.php (6.4" display) And I paired it w

I did buy this phone http://www.gsmarena.com/sony_xperia_z_ultra-5540.php http://www.gsmarena.com/sony_xperia_z_ultra-5540.php (6.4" display) And I paired it with an apple bluetooth keyboard. But the display is too weak for sunny days. Even in the shaded parts of the park, it's almost impossible to work. Maybe some phones/phablets/tablets are better suited for this than others?