Kitkat for Xperia Z1 is finally out..hopefully it improves the camera and add Z2 functions...
But so far people are reporting no significant improvements. Sucks...
I'll probably skip the Z2 and just go with the New HTC one...if Sony can't even support a 6 month old device even if they have a fix for it. Maybe that's why they releasing a new flagship phone every 6 months...
The camera has been improved. Pictures have much less noise in them after 4.4.2, it won't be the same as the Z2 because it uses a newer version of the sensor (like the RX100 to RX100II) that is better in low and high ISO and it includes a couple of lens adjustments for sharpness. I think the module number is the same, but the actual sensor and lens are every so slightly different (improved). That goes beyond software though. Regardless, the software side is significantly better than before, no more mosquito noise, more detail (more grain also), NR has been set to off for low ISO pictures, the file sizes are also bigger iirc.
The people reporting are either not taking pictures right or they are not doing like-for-like comparisons.
http://www.static.xperiablog.net/wp-content/uploads/2014/03/20MP.jpg
Have a look at that picture at 100%, you can see a proper grain pattern rather than compression artifacts or mosquito noise from previous pictures. In general compression is much lower now.
Even then I think there is more to come on the software side for the Z1 and Z1c, however, they won't deliver that (timeshift video and 4k) until the Z2 is on the market. Those flagship features would need to come to the flagship phone first and then be rolled out to compatible devices later on.
One downside I have heard (and had confirmed) for 4.4.2 is that there are a couple of battery drain bugs for the Z1 that they will need to get ironed out very quickly. Hopefully the next software revision fixes those. Personally I wouldn't update to 4.4.2 until they fix those. Sadly my ZL will have to wait until May for 4.4.2 and my SP will be waiting until June/July.