On October 1, I received an upgrade for my Sony Xperia M2 from Android 4.4 to 5.1. I hesitated for a while, but after a few hours I installed it out of curiosity. I had only skimmed a few pages where people reviewed mostly Sony phones and their upgrades. If anything, the battery life was getting better, so I wanted to believe it, but it kept nagging at me, since I know how upgrades have always turned out for me. So I reset the phone to factory settings twice in a row and then updated it through the PC, because it was not an OTA update. The phone restarted a few times and then the individual system components were upgraded. What pleased me at that moment was that the progress bar was a deep orange, one of my favorite colors.
I entered my PIN and was in the system. I immediately checked how much time the battery had left before it died, and it was not much, but I told myself the phone was working at full throttle right now, so there was no need to throw in the towel yet. I do not know what this bad habit of Android is, but unless everything is left at default settings, battery life drops a lot. Paradoxically, more apps and features mean better battery life. I turned off almost everything, uninstalled everything I could (unlike Android 4.4, everything could be removed) and thought I had at least partly won. But I had not.
Battery life dropped to about 3 days on standby with Stamina. When I played with the phone nonstop, it lasted about 12 hours. I told myself no way, because I was used to about 2 days of battery life under fairly heavy use. I did not even try to look online for how to downgrade, and since I gave my ordinary Lumia to a friend yesterday, today I went to buy a new one. I knew which one, but it came in 2 variants – single SIM with LTE or dual SIM with 3G.
Had I known that 3G would run so well on the Lumia, I would probably have gone for the dual SIM one, but LTE was such a big temptation that I will simply put the VF SIM card away in a drawer, or I will swap it depending on where I still have FUP data left :D. I was heading home from Exasoft and turned the phone on. Its speed surprised me, everything was almost lightning fast. I had been losing faith in WP, but this phone restored it, and even though it is about 1,500 CZK cheaper than the Xperia, it is better in many respects – a bigger, higher-quality display, better LTE and 3G reception (only when both 2 devices sit side by side, each on a different SIM card, the Xperia is fast as always, while the Lumia cowers in the corner), and a louder speaker and earpiece.
At home I then connected the phone to a fully charged Xiaomi power bank. I could have used a charger or the PC, but I knew I would be measuring speeds all over the place, so the power bank came in handy. It took about 2 hours to charge from 30%, which is not an amazing figure either, considering the power bank has much more output than a PC or charger. Many people are afraid of WP because they think there are no apps for it. I can agree with that. I would also like an official app for my Nikon camera and the Xiaomi Yi, and for the rest to be better and more mature. But WP would be enough for 90% of people.
There is some unofficial app for the Xiaomi Yi with a rating of about 90% that looks very nice, but when I take a photo, it says the photo was taken, yet I cannot find it on the phone. Only while writing this blog post did I realize that it gets saved to the internal memory of the Yi! So the app works, but I cannot share the photos anywhere, unless I move the MicroSD card from the Yi to the phone. Still, the official Xiaomi app on Android works exactly the same way, and the one for WP is still in development, so maybe we will get this feature too. This is how it takes photos: 
Personally, I am quite curious about Windows 10 Mobile. Today is exactly the day MS officially unveiled Windows 10 Mobile and the devices in its ecosystem, including 2 flagship Lumias that you can connect to a monitor and get a full-fledged PC (!). You can read about it, nicely illustrated, for example here: https://mobilenet.cz/clanky/microsoft-predstavuje-windows-10-mobile-a-lumie-sledujte-on-line-28453 . The article also mentions the Band 2 wristband. My Lumia already comes with the Fitbit and Health and Fitness apps preinstalled. I like that too, because I enjoy at least taking long walks. Like most apps, these can of course be completely uninstalled if you do not want them. I have not even tried half of the apps that were there, and I do not know whether I will or whether I will just uninstall them right away. It keeps spying on me and tracks my every step, and it apparently cannot even be turned off completely, except by switching off GPS altogether. And that is even though no fitness device has ever been connected to the phone.
So far I am not happy with the battery life and I somewhat regret buying the phone. But I have always been much happier with the battery life of WP than with Android, and this one has a 2,500 mAh battery compared to 2,300 mAh in the Xperia. Yet people praised it so much in reviews compared to Android, so I have to ask – did I get a faulty unit? :/ If I use the phone heavily nonstop, the Lumia lasts maybe even less than the Xperia with Android 5.1. This is not quite how I imagined it. It is true that I have everything turned on, including brightness at max, and that this matches the experience of other owners, but I was so starry-eyed that I hoped for something better.
Android already has pretty poor battery life, and manufacturers should only upgrade the version when it guarantees the same or better user experience. A 75% drop in battery life is not what I consider that. No thanks to Sony for this. I probably would not have upgraded if Sony had not kept pushing it on me. The phone used to last at least 10 days switched on; today, if it lasts 3, it is a genuine miracle. Personally, I am afraid of W10M. After all, PCs are much more demanding on the battery than phones, so I hope Windows 10 Mobile will maintain continuity in battery life.
One of the latest Insider program builds, 10512, reportedly brought battery life back to values similar to WP8.1. Let us just hope it is not a hoax by journalists or Microsoft. The Lumia was always better at playing songs or radio, even though it had a considerably smaller battery. I think that will be the case now too. Overall, I rate the phone 80%. It is great in some ways, but in some things it has not yet convinced me of its qualities and I expected more from it. That is not the fault of Windows Phone 8.1, though – I mean more the HW things – the missing HW shutter button, the battery, the not-so-exclusive and eccentric design, and so on.