[One (M7) General] Xerro-Five:
Hi all! Well I finally exchanged my One because of the red noise issue that has been well described here on xda, so I thought I'd post my observations on how a phone built in March compares to one built in June.

First one: manufactured in Taiwan, March 9th

New one: manufactured in Taiwan, June 25th

First of all, I'm happy to report the red noise is gone :D feels like freedom! Hopefully it doesn't develop again but so far nothing I've done has caused the noise (putting it down on a table, using when warm (<35 degrees) etc.) So hopefully this means htc changed their sensor in some way so as to prevent the issue which is clearly hardware and can't be fixed through software updates for most people. The new sensor was manufactured on June 19th. Considering 86% of users report the issue http//xdaforums.com/showthread.php?t=2317507 it's pretty unlikely I just got lucky on this one (why I am optimistic new sensors are different).

The build quality is also better than my first. The first wasn't bad compared to many people who had gap and screen problems, but there were some overhangs and poorly machined parts. The new one is perfect... Completely. So again hopefully this indicates they have improved their manufacturing and QC processes. Considering how prevalent these issues were at launch, it's pretty unlikely I got lucky twice rather than them improving QC IMO).

The display is also better. This probably isn't a batch specific thing since they use multiple suppliers (2 that I know of - sharp with renesas controller and JDI with Samsung controller). The first was a JDI and had very good brightness, black level, and a cooler white balance. The new one is also a JDI. It has a Warmer white balance though (I prefer cooler, even though warmer ones like the new one produce more accurate colors) and the contrast has improved quite a bit. Brightness is roughly the same between the two. Normally warmer white balance is seen in the Sharp displays from what I understand http://xdaforums.com/showthread.php?t=2202869. Perhaps it's not as warm as a sharp panel would be though since they seem pretty rare and I've never encountered one.

They seem to have changed the vibration motor because this one doesn't shake the table when it goes off ;) seriously the first one was excessive. It also made an annoying noise when it went off. The new one is much quieter and smoother. It feels more like how my old iPhone 4s was (if you've had one, you know this is a good thing!)

They've changed the usb cable - the ends are rubber now instead of the hard plastic that was on the first one. Small change, makes it feel better to me.

So overall everything seems to be a change for the positive. I'm not sure if I got the STM hdr mic or not, though since the judgement was passed in April I'd be inclined to think they would still have decent stock a month later at least. Hopefully stock holds out! So if you've been waiting to exchange for fear of getting one with poor build quality or a camera sensor that's just as bad, maybe these observations indicate that it's safe now. I really hope so...

If there's something else you'd like to know, I'd be happy to try and compare :)