I switched from Dalvik to ART two days ago and haven't found anything that does not work. After choosing ART in developer options, I performed a cache clear and that took almost as long as switching to ART.
The first start up of some applications does take time, be patient and it will get there. Succeeding start ups may be slightly faster than Dalvik but not a major step forward.
My perception is that the display is quicker and smoother. The display looks brighter to me.....so much so that I checked to see if the brightness had switched from auto to max......and it had not.
I consume a lot of data during the day, and battery would usually be in the 40% range by evening, but today it is at 60%. No real measurements, but all additional battery life is welcomed.
23.3.24.obake-maxx_verizon.Verizon.en.US