LG seems a bit cheap to me and lacking quality overall as a brand. Maybe it's just my experience with other products but as a company they don't excite me. It was a tough choice for me between the S5 the Xperia Z2 and the M8. Ultimately the M8 won out for me. LG isn't really exciting me very much. I've sworn off Samsung as I was extremely dissatisfied with my Galaxy S2 a long time ago. I had nearly sworn off android all together after owning a Lumia 920 but I'm back now.
I'm pretty happy with my M8. I have it rooted with elementalx kernel and running art. It's fast. Battery life is good. I'm down about 40-50% after a long day listening to music 3hrs with a USB dac and browsing reddit all the while. I definitely give it some abuse on the battery. I love the Sense UI. Does everything I need it too. Never have a problem getting LTE and regularly download at speeds of 45-50 mbps.
Why would I take the LG over the M8 aside from the bigger screen? My friend bought an S5 after I told him not and afterwards had regrets. He's telling me the screen is even too big for him. I passed on the Z2 because it would just be a bit too big in hand.
I'm not too concerned about camera as I have a wide angle lens dslr that I don't even use enough. For me the phone camera is only useful to send selfies to women I am trying to date. 5mp is enough detail for my ugly face

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