I recommend to use the latest TWRP build.
On the first install, a factory reset is recommended.
1. Do a backup
2. Install ROM
3. Optionally, install GAPPS
If you're updating, you can just install the newer ROM zip then reboot, as it won't delete the GAPPS. You can also use the built-in updater.
There should be only one bug: wallpapers wider than 2048px can't be set. Sadly, the default Google wallpapers may be bigger than that, so setting those may just result in a black wallpaper.
Got any other bug? Report in this thread - I'm subscribed, so I'll get e-mail notification about the posts... I am your device maintainer
OmniROM, ROM for the Acer Iconia A700 and A510
Ziyan, Shreps, Elibl
ROM OS Version: 4.4.x KitKat
ROM Kernel: Linux 3.1.x
Last Updated 2014-09-23