You have used xperia Z2 and Lg G2 both before so i think you can help me out here. If i ask you to choose one out of two for free, i.e. LG G2 or Xperia Z1 what would you pick?
Me personally, id go with the xperia. Such a premium feeling device with waterproofing (which is good since 1 device ive had died due to water..) and the stock rom is by far one of the best IMO, if not the best. The camera quality was relatively equal but the z2 seemed to film better (or at least at a higher consistent framerate while the g2 even with 60fps selected can drop frames). Only issue is that there is a lack of development for the z2. Sure there are some roms and kernels, but there arent as many roms and kernels there when compared to the g2 (this is z2 development, z1 may be different). The speaker of the z2 was much better as well (however, the z1 is probably worse than the z2 and equal to the g2).
In the end, id still choose the xperia... Such a shame mine cracked so easily as they're generally really tough devices.
The battery life of the z2 was also noticably better in my own experience, however, thats probably due to the stamina mode included.
My only issue is that this is my experience with the Z2, not Z1. They are similar devices but not identical and a lot of the pluses of the z2 i listed might not be in the z1. (Like speaker or battery life)