The gold standard, IIRC, was for apps to get launched and be able to do something in 2 seconds or less under Dalvik in common use.
You're waiting between 300 and 600 seconds, one time, and still waiting for apps to launch (which I'm sure is not instantaneous with ART, no matter your hardware).
My daily-driver is a Galaxy S5. It is, by most measures, a rather fast phone in terms of internal storage speed and CPU grunt. I don't notice much (any, really) difference in loading apps between 4.4.4 (Dalvik) and 5.0 (ART) on this device. But I do notice the "Android is upgrading...." process taking much longer with ART than Dalvik when tinkering, as I also did when experimenting with ART on the Bionic before Lollipop made ART a default thing and the Bionic was my daily.
Also, too: You seem to dismiss the notion that Dalvik is not exactly JIT: It is absolutely JIT on first load, and then largely-compiled apps get stored in the (not-accidentally-named) Dalvik cache for quick loading later.
I'm not sure that we, given our combined experiences, can say which one is better. It'd be awesome if I could find a Google study of actual performance instead a Google proclamation of things to come, but they're Google and therefore always in a forward-thinking perpetual beta with no rearview mirror: Whatsa behind me, is not important.