It work with new legacy Xperia. But davik run more stable and better compatility.
Facebook run much slower with ART turn on.
conclusion, ART now for testing, not worth to turn it on yet.
I always have problem when I activate ART on my lww. after 2-3 normal reboots the system turns back Dalvik on and erases all my cache. So I don't know what is the best until now.