After coming back from vacation and having had some time before my next trip I decided it was a good time to upgrade my Samsung Galaxy S4 from CyanogenMod Android 4.4.4 (Kitkat) to 5.1.1 (Lollipop) mostly because of the Stagefright security issues discovered in the weeks before. While that fixed the security issues I was actually positively surprised about a number of new and different things on Lollipop (i.e. CyanogenMod 12.1). Read on for the details.
First of all, the eye candy has gotten slicker again. Things roll in and out of the screen into different directions and animations are much smoother. Despite the added animation complexity there's a noticeable improvement of the calendar entries being presented in a widget on the start screen. Instead of taking 15 second they appear immediately.
Also, program startup times have been much reduced and, what I've been asking for a long time, apps are no longer terminated in the background after some time of non-use or when bigger apps such as Osmand are started in the foreground. Also, switching between running apps with the new task switching functionality that shows running apps like they were in a Rolodex is much better than on Kitkat. Another thing that has gotten attention was the startup time of the camera app. While it usually took several seconds before, it's now almost instantaneous.
Speaking about Osmand, the GUI of the current version that was released independently of my OS upgrade has become much slicker. It took a bit of time to get accustomed to where I find different functions as they look a bit different now but overall I like the user interface changes.
Further on the positive list, a '#' sign is now shown in the status bar if an app is running with root rights. Speaking of the status bar, I like the new icon design and notification handling both in locked and unlocked state and the ability to completely block notifications of apps that I don't want or only ban them from the lock screen.
And last but not least, my network blocking scripts to remove obnoxious advertisement in web pages and the ability to disable GSM for LTE/UMTS only access still work. Excellent, both are must-have features for me.
Unfortunately there are a number of major issues with the CM 12.1 nightly development stream as well: Nightlies distributed in the middle of August for the S4 had a major problem with the GPS chip and my device couldn't get a fix at all or took several minutes. This seems to have been fixed in late August but the current nightlies keep soft resetting the GUI several times a day on my device. I tried an S5 for comparison and had the same experience with soft resets. I guess some more work needs to go into CM 12.1 before it can be declared reasonably stable and usable. A bit of a pity, I'd really like to use it now :-)
The second issue I have noticed is power consumption. I can't yet put my finger on it but it seems that while power consumption is the same as before when the phone is locked, significantly more power is required with CM 12.1 while the device is used.
Well, I guess you can't have it all, but the broken GPS functionality and regular GUI resets are a showstopper for me at the moment. Fortunately the Galaxy S4 CM maintainer has now issued CM 11 nightlies with the Stagefright fix as well. So let's see, hopefully that's more stable.
Not so easy I'm afraid...