[Xperia Z2 General] _delice_doluca_:
In Sony world, it is mostly personal preference. If it was a Samsung phone I would no doubt say "go for it and never look back". For a Sony, it is just you have more than one option.

What you get with Sony's stock over a pure(ish) Android;

-Options to have ClearAudio+ and XReality technologies which helps to improve music and image quality respectively from Sony.

- Stamina Mod. Without turning up and down bars into orange :)

- Picture correcting software which is heavily integrated into original camera software and protected by famous DRM keys. It helps smoothing the noise on the photos, coming mostly from lack of enough light. Especially night shots really benefit from it (difference not so visible on day light).

- FM Radio and some software of Sony like Playstation center and internal backup and restore software, also an Antivirus if anyone is interested in.

Bad side of Sony's software over Pure Android:

- the theme you apply directly effects the top bar. I love red and red-like colors but I don't wanna use my whatsapp with a cherry red line on top. I was hoping that would change in 5.1.1 but no luck.

- standby drain is high if no Stamina is on. Something between 5-10% over night. That's absurd considering the usage drain is fairly good.

- all those beautiful camera options only limited to 8mp option. 12mp is just pure photo (still combined with Sony's correction software if DRMs are active)

- when I try to fast scroll, sometimes the launcher jumps two pages at a time but that happens only going to the right, not happening when going to the left :)

- I don't know if it's only my phone but most of the time turning on the WiFi is not enough for it to auto connect to a remembered network. I have to open the network list and click on it to connect.

So, what CM or other pure Android-based ROMs offer:

- visual consistentcy among all the apps and menus. Once use stock Android you understand how odd the later added apps look in modified versions. For example Google photos and Google calendar has very familiar look and feel and behaviours. So once you get used to them you can immediately and efficiently start using Google Messages too. However that is not the case with Sony's Album or Walkman app no matter they have their functional advantages.

- super fast, super light, super light on the battery.

- sound and camera may need some fine tuning to reach to Sony level but it is possible as this device have is well known by developers and shares a very generous, open code. For example OpenCam app is perfect for doing anything you want to do with your camera, and it also comes without Mp limitations.

- there are some neat additions to original Android like theme engine or assigning volume keys to change the song or reordering the tiles on the top bar.

- per app ops to limit untrusted apps' intentions.

- more options through Xposed as it is created from a widely shared code.

The cons:

- since most of the works are based on nightlies, sometimes things can be broken for a couple of days or something working might stop working after an update. So you must decide between a tester and a careful everyday user who comes one or two days after the testers on the update schedule.

- you should find you DRM keys a safe place before unlocking your bootloader (I keep mine on Google drive) as they will be gone in order to be able to install a non-Sony ROM.

- camera quality may degrade if you are fan of super auto mod especially (personally, not).

- Xreality will not be there as it is a Sony extension. However I personally think this beautiful screen does not need any tuning to show the beauty of anything.

- no FM radio or pre installed anti virus software.