I bought my XZ Dual last December, and here's my personal view on it so far;

It feels premium, and at the point of buying it, it was one of the best high end smartphone available at the time. There was nothing really to complain about, until a few months of heavy usage.

I consider myself as a heavy user; switching from one app to another, playing games continuously, constantly taking pictures and videos, streaming videos, browsing social media at times, and using chat apps one after another.

Sure at first it was flawless without a hint of lag. However after only 3 months of using it, it started to lag and apps were crashing and lagging, especially when I played highly demanding games such as Asphalt 8, NOVA and even Mobile Legends. And at this point, my memory usage was only 50%++ of its physical memory. And with each update they rolled out, it feels more lag than the previous. Not to mention that the device itself would heat up considerably, unless you are playing it inside an air conditioned room.

Continuous use of the camera also pose another problem in a country like our's. It heats up very fast after few shots or after few minutes of recording in HD. Its gotten to a point (multiple times) where only basic camera function was available because the device was getting too hot. Sometimes it just shuts you off, due to the temperature increase, and you are unable to use it.

It feels premium while holding it, sure the resultant pictures and videos are something to boast about, and the screen is beautiful especially when watching HD videos, but with only 3GB of RAM I don't think it is even relevant for power users anymore in 2017 when apps are getting more and more memory demanding and users are getting ever greedier (even me) and are expecting more from a brand that they know and loved. Its a flagship product at the time of launching, but after only 2 months or so, other brands had rolled out even far more superior phone when compared to this.

By resetting, do you mean a factory reset? If so, then obviously it will achieve the same fast no lag as when I bought it. I don't mind if the phone lags a bit in comparison with when I bought it, since I had installed tons of apps and use it for quite some time, but the lag is unfortunately not one would expect a phone of this level would perform.

My main concern and complaint right now is with continuous use under certain condition, it would heat up too much for a phone this level. And I'm actually quite disappointed with it. And when it heats up, it'll lag more.

I seriously hope Sony would actually resolve this issue, sooner rather than later. Or else, they'll risk of losing even more customers than before. Even the android OS is using 1.3GB of RAM at all times, I wish they could make it use even less than that.

It is very disappointing.

My Z2 is a much stable phone too, so I get what you mean. My longest was 30++ days without restart and it won't lag much, but with my XZ a week is the most right now I can go on without having to restart the phone due to the phone going much slower than a toddler learning how to crawl.

Yeah just notified by it. Hopefully it would fix the lag.

For RAM usage, mine is running around 2.4GB at all times, and that is even when I force close tons of apps that I rarely use.

Even after the update, my phone still feels laggy. And does anybody notice about the tap to wake function? It was supposed to be tap twice to wake it, but mine needed more than twice, sometimes even more than 4-5 times tapping quite hard on the screen, then it'll wake it lazy ass up.

Even the adaptive brightness function seems to have a problem. It doesn't adapt to the changes in brightness fast enough, sometimes it would actually stay full bright or half even in total darkness and I had to manually change the brightness, which makes the function seems wasted. It doesn't start on this update though; if I'm remembering it right, it started since the last 2 (or 3 update).

Mind you I don't even put on any screen protector anymore, and I regularly wipe my screen with glassess cleaning cloth.

The tap to wake problem with mine I think is due to the high usage of RAM at all time, hence when I tap (or knock it) it would need more than twice most of the time.

I do think its about time I do a factory reset on my XZ cause I have been facing tons of issues, but I just don't feel satisfied for a phone of this level to perform this way. Maybe it is just my unit, or my batch of unit, I don't know.

I do think Sony might have a problem with RAM management issue in the long run because this is the same issue with my Z2 last time. Hopefully they will manage to fix this soon.

Aaaaaaaand this is how hard reality slaps me in the face. Then Sony better fix the ROM asap. Or we can just hope that they will.

It was actually one of the few apps that I already disabled, but the performance in terms of gaming is still sub-par for a phone at this level. I even disabled facebook, zalora, tips & tricks and a few other apps. It really doesn't help much.