A couple of days ago a system dump for the Nexus 4 led to all of us being able to run Android 4.3 before it even was released by Google. The real question lies now in how well it runs and whether I would recommend flashing it to your phone. After all, I've been running it since the moment I found out about it so I have had a little bit of time to experience everything it has to offer. I'm also going to preface my review by saying that the system dump that we have seen on the Nexus 4 which is also the same as the one which became available for the Galaxy S4 Google Edition a few weeks ago (Build JWR66N) was compiled more than a month ago, on June 15th. That being said, it is very likely that these are not the final build that will be coming out as an OTA in the coming weeks.
The Camera application
As we found out from the software that came on the Google Edition phones, Google had a new version of the Camera for us that would make it easier to change the settings when taking a picture because the older version (from 4.2) made a circle of icons around your finger and it was difficult to see what you were doing because your finger would always be blocking part of your view. The new camera app makes an arc of new icons over the top of where you touch so you can see all of the icons clearly from the same vantage point. (See photo).
The Phone application
The most important application on your smartphone is the one which is also the most neglected; the phone. Admittedly, for a lot of people it might not be the most important app, in fact some people may not even use it at all but the fact remains that it's called a 'smartphone' for a reason. The phone app in android 4.3 has been tweaked just a little bit to allow for T9 dialing. If you are unaware or don't remember what that means, it simply means that you can type a person's name into the dialer rather than their number (notice I typed John using the dial pad) and it will suggest the closest contact for you to call. This feature is not enabled right away, however, so you need to go to the phone app settings and turn on dial pad autocomplete.
Google has promised with the next update they would bring us Bluetooth low-energy and as promised, they have delivered. I can confirm that although I have had Bluetooth on almost constantly since flashing the update, I have had comparable battery life to what I had on 4.2.2. In fact, I may even be getting better battery life than I was before but it's hard to tell since my usage varies from day to day. But that does bring us to the second point of interest, the WiFi radio. It's always on. Even if you "turn it off" it's still scanning for WiFi access points. Why? Well, it's probably to save battery. I know your head is probably already spinning but think about it this way. Google has a massive database of where every WiFi access point in the world is and every time you connect to or your phone just sees a new one you're adding to that database. If you keep your WiFi radio on all the time, most of your apps can get their full of location just by using WiFi and never having to turn on the GPS locator chip which uses a lot more battery. So, in short, you're saving your battery by constantly scanning for WiFi access points. It's a little weird, but it seems to be working.
It's kind of funny, really, how people expect this to be really laggy just because it hasn't been announced yet. I've even heard people call these leaks "crap" because they aren't officially OTA updates. One thing you need to remember is that this software was being used by someone within Google on a real daily-driver Nexus 4. It had to be able to do the job for him or her and it's doing the job just fine for us. A friend asked me the other day how I thought it was in terms of responsiveness and I will tell you exactly the same thing that I told him. Without running any benchmarks, I couldn't tell you the difference between 4.2.2 and this 4.3 leak. That being said, it's possible that this is beta software anyway, and it will be completely different from what is released in a few weeks.
I'm not ignorant and I pretty much understand how SU works on a Linux setup but in Android 4.3... something is... different. I am not really sure what it is, perhaps it is a security thing, perhaps it is a memory thing. +Chainfire might be able to tell you a little more since he has been able to find a workaround to get his own app to grant superuser permissions but something still isn't right. I have tried to make changes to my /system/app folder using Solid Explorer and I just keep getting an error stating that the directory that I'm trying to copy a file from (/storage/emulated/Download) doesn't exist. My guess at this point is that the OTA update is going to tweak the file system and that we are trying to do something that was never meant to be a problem to begin with because this software wasn't meant to leak before the release. At any rate, it's something you will have to deal with if you choose to flash this leaked software.
One thing that has sort of been an eye sore since flashing this update is the notification shade is now littered with useless notifications that some applications have to push in order to keep the OS aware that it is still there and active. Things like security apps and tasker need it so that they can stay on top of things. In Android 4.0 - 4.2.2 you could go to the app info and disable notifications for those apps so that you didn't have useless notifications in your notification shade all the time but in 4.3 (or at least in this leak) that is not an option. You can still go to the app info and re-disable the notifications but that will only last until the next time you reboot and for me, that's too much of a hassle. I'm sure that there is a reason that Google is doing this, perhaps it is a security measure so that apps can't force themselves to work in the background all the time without your knowledge but that is something we will hopefully find out more about when the OS is officially announced.
Overall, this leak seems to be a very close to production-ready beta. Whether or not this is the actual build that will be rolled out as an OTA still remains to be seen but I'm still putting my money on "no." I think there are still a few kinks to be worked out before Google would release this, especially since their last major point release (4.2) was cleaned up by the two following smaller point releases (4.2.1 & 4.2.2). If you're itching to just flash your little heart out, I would say do so with caution and remember that you are holding a Nexus device which means that you will be getting the real update very soon after the official announcement is made which I'm guessing is going to be next Wednesday. In reality, there isn't much to look forward to here unless you use Bluetooth all the time and even then, it might be worth just keeping your phone cherry and waiting for the real update. I would say in particular, that if you are one that uses root for a lot of things that you should probably wait for the real update and see what all of the developers can do in terms of getting root working properly.
Have you tried the 4.3 leak on your device? Have your experiences differed from mine, and if so, how? Leave your answers in the comment section below or spark up a conversation on the original post on Facebook or Google+!