From my experience, even on Dalvik, Kitkat really uses a small amount of ram, IIRC about 300MB without any 3rd party apps running. And after I enabled ART, i see that it apps opens up faster, almost instant. Downside at the moment is some apps just refuse to open using ART, straight away FC...and you are right on the CPU part as I notice no significant increase in synthetic benchmarks. User experience is greatly increased though with the faster app load time.

Baterry bit better
Transparent bar enabled
Lil low memory usage
More under the hood change

Guys, help! I tried to update my gf's Nexus 4 OTA, but no system update. I read about this and decided to try it.

clear cache, clear data and force stop for below Apps

1. Google Play Store
2. Google Play Service
3. Google Service Framework

And now my Play Store I can't dl or update apps, it keeps pop up the error. Error retrieving information from system. I tried restarting the phone but the problem persist.

Like that we don't know whether connect to internet access onot.....