Wow, coincidence. Yesterday I also decided to revert to dalvik so I could use xposed.
However, upon reboot and app update I found that /system was read only and I couldn't install xposed; also I lost root and AFWall+ no longer worked (that's how I realized I'd lost root).
As I was on my way out to meet friends, I didn't have time to fault-find, so I restored my nandroid and I'm back on ART.
I think I'll have another go today.
funky, I was thinking... if gravitybox has so much customization, we might as well flash pure Omni with minimum customization - particularly as the dev of gravitybox says it is best to use with AOSP roms with no customization because of conflicts between rom customizations and the module's customizations.
I might do a clean Omni flash as I tried Slimkat yesterday and all the icons were too small - including the clock etc in the notification bar. I gave up in the end trying to fix it and went back to Temasek.