I have to say, my experience of custom ROM support for this device (311) has put me off using them in future.
Depending on which custom ROM you choose, there are problems with GPS or sound stutter or HDMI or all & more
I've gone back to rooted stock Sony - it's so nice that everything just works
Phone : Sony Xperia Z2 running stock Sony kitkat 4.4.2
Tablet : Xperia Tablet Z (311, 16GB WiFi only), back to Sony (KK 4.4.2) ROM for a try!