Share your experience!
Hi, I need some help. I purcashed this phone for about 21 months ago (if I'm not mistaken). I don't know whether I'm lucky or not, problems on my phone started after my warranty is over.
The first problem is touchscreen error while charging or connecting it with usb cable. But I didn't take it seriously because the touchscreen problem was only occur in that condition. I was wrong. Lately, the touch screen problem become worse. I even barely type a full sentence, barely open my phone lock (as well as when someone call me), and using it is like.. breath taking. I can't even swipe the screen or scroll it!
I've searched trough google and forums on this web and found out some people do "sunbathing" to solve it. But I'm not really sure to do it. Doesn't it will damage the device if it is over heated?
And the second problem is occur on my device's display. It happens several times. Suddenly each font below all of my application changed into something like white thick barcode. I was shocked that time and lock my phone and unlock it again. And in my shock, it disappear! But recently it become more frequent. And I dont know what to do. Also when I'm typing, nothing is appeared on the screen (It's only appeared on suggested word colomn). I lock and unlocking my device again and I also restarted my device if that doesn't help. Sometimes it worked and sometimes it don't.
The third problem is lagging. On some specific application it often freeze (Facebook, Message, etc). On Facebook (that can't be uninstalled) it freezes so long whenever I tried to use it and make my device so hot. While in message, when I opened it, nothing is appeared. I tought it still loading or something and I waited it. But after some minutes nothing happen. Sometimes it says "no conversation, tap the icon .....".
The fourth problem is the connection on my laptop. I wanted to clean up my device's media, because I guess it is one of many causes (which I don't know what are the other) that make my phone lagging. But everytime I tried to move my media to my laptop, it says that it can't read the specified device. I've tried it several times and nothing changed. My phone can't really connected to my laptop. It is like connected-unconnected-connected-unconnected-.... (for so many times). So I unplug the cable (both on my laptop and my device) and plug it again after several minutes. But still, it doesn't work.
Now, I don't really know what to do it's like really.. I can't connect it to laptop and what should I do to repair it. Too many problems occur. But I'm still love this phone and don't want to throw it. Please, I need a hand! 
p.s. I'm not an expert on things like this and anyway, sorry for my bad English 
It's nice to read this.
I have the same problems. Applicactions lagging and screen lagging are the worst, all others are just a matter of resetting from time to time.
I say it's nice because Sony Support treat me as if it was a very rare problem and mine was the first (and unsolvable) case.
I know it's no help, but a friend with another Sony and I always refer to our phones as "Desperia".
I have just repaired and unlocked an old gingerbread based phone a relative was not using. Being older it just works better.
I will keep with my desperia as long as I can, I cannot afford buying a new phone every year just to see it it works better, but as of today it will not be sony.
Sorry.