[Xperia Z1 Compact Q&A, Help & Troubleshooting] GuizmoPhil:
Good thing for me that went from .114 directly to .757 (i am rooted also)

Camera app have now a 15Meg option

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Bad things

Conversations.apk (the SMS/MMS app from Sony) is full of bugs. And when I mean full, I really mean it.

Sometimes messages that i already read in the conversations, disappears. All I would see is the blue bubble showing that there's a message, but without the text of the messages. So far this seems to only affect SMS, not MMS.

The color of the bubble when you type, let say blue, and the color of the bubble of the other person talking to you, let say faded blue, often get switch, so reading a conversation might become difficult.

To get the difficulty level higher in following your conversation, sometimes even the side of the screen your bubble is supposed to be attached switch. I mean here, that when you type, your message is next to right side, and your friends reply is next to left side. But now, sometimes you switch side all of a sudden, or worst, sometimes you're on the same side then your interlocutor. Reading SMS with the conversation.apk is totally hardcore now.

Another thing that really piss be off, but I do not know if this is from 757 or if it was already in 114, since I did not use this app in 114, it is the Email software. The Email software stacks/bundles all the messages with the same subjet title when someone reply or transfer your email. (like Gmail does in a browser by default). I really hate this functionality, I prefer to just scroll down to see the previous message if I need to. Unfortunately for me, there's no option in the app to unstack/ungroup emails messages.

Another problem I have with the Email app, this is a bug, because it wasn't doing this in previous build, it is that the Small yellow icon on the icon that tells you that there's 1,2,3 what ever number unread messages, and also the Mail icon in the notification bar, does not go away upon opening the email message. You need to actually press the back button to exit the new messages for it to be marked as read, so that the icon and the notification bar adjust. So if you open an email messages, press the home button to do whatever else, then look back at your notification bar or email icon, you'll think you got new email message, but in fact, it's the same one that is still marked as unread, even if you did open it and read it...

Email and SMS/MMS apps are what I use the most on my phone, I've been using them since I got my first Xperia X10 Mini Pro that was running 1.6, but I've never had that much trouble, they have so many annoying bugs right now. The only problem I've had was the notification LED bug on my Xperia Mini Pro running ICS.

Another thing that I hate, but this is not from 757, but from JellyBean. I come from ICS, and what I hate the most, is the damn white background of all apps. It use more battery and it hurts my eyes in low light room even with minimum brightness. I just wish a stable CyanogenMod with black background pops like in ICS so that I can install it. I've seen some topic about it over here, but they only explain how to uncompile and recompile, too much complicated, I'd rather simply have a package I could simply install with CWM.

EDIT: Oh yeah, I forgot to mention another bug. Somehow the auto-rotate of the screen stopped working twice in the last 2 weeks. Each time I need to go in the accessibility options and uncheck/recheck the auto-rotate option to fix this. (grrr need to wait 5 minutes to be able to edit my msg #xdaforumantispam)