Over the weekend, I spent some time with the Nexus 5 running both on Dalvik and on ART. So I figured, that I should probably put together a nice post detailing how well it works for typical users like you and me, instead of developers and OEMs that build phones. First of all, if you want to use ART there are a few things we should warn you about. So far it looks like only a handful of apps are incompatible and those include Whatsapp, and Titanium Backup. Those are the only two that I ran into problems with. Now there are probably more, but I didn't test all the apps in the Play Store. Secondly, if you want to use ART, you'll want to enable it before installing all your apps. Or it's going to take a very long time to reboot and update all your apps.
I know the first thing you're wondering about Dalvik and ART is the battery life difference, well we've got screenshots below. Both cycles were on WiFi the entire time, and had basically the same use. Although in the ART one, you'll notice Cell Standby is pretty high. Its because I had removed my SIM and reinserted it in the last hour of the cycle. I was then afraid to restart the phone as it might mess up the stats. So the first image below is on Dalvik the second is on ART.
Next up is a speed comparison to Dalvik. Now since I actually do have two Nexus 5's here, I figure it was the perfect time to do a Dalvik vs ART comparison on video for you. Both devices are on WiFi, and have been turned off for about 30 minutes before filming, so we can see which one starts up the fastest. Also they all have the same apps installed. All the stock ones plus Twitter, Dead Trigger 2 and Speedtest.net. That you can see down below.
It appears that ART doesn't seem to work too well on devices other than the Nexus 5. Which kind of sucks right now, but I'm guessing it'll be optimized for other devices soon. Maybe not until after Google has finished that project. If you're still looking for more information on ART and Dalvik, Jeremiah did a great post last week explaining what exactly ART is.
If you've got any questions about ART, feel free to drop them down below and I'll do my best to try to answer them.