Originally Posted by binary visions
I haven't switched to ART on my Moto X yet because I generally treat me phone as needing to be stable all the time. I did switch to ART on my Nexus 7, though, and most apps worked just fine. My Yahoo Sports app experiences a very long delay (~5 seconds) when I try to look at any individual game stats for the first time after I open the app.
My NFL Sunday Ticket app also doesn't appear to be as stable, sometimes force closing which I didn't usually get before, but I haven't done back-to-back testing to see if it's actual cause/effect.
I just switched to ART last night on my moto x and am having the same experience you detail. If an app is already open, its lightening fast to respond/open back up. But some apps when opening for the first time take longer than they did on dalvik. Facebook for instance, takes nearly twice as long to initially open.
Tip (if you havent already) - under developer options, change the window, transition and animator duration to .5 seconds (down from 1 second). Its literally instantaneous moving between apps and such.