I had all Galaxy S devices and I enjoyed developing for them but I trade my S4 for the following reasons.
1. Knox bootloader, 2. Camera on my S3 was better in zooming than my S4, 3, same **** like Iphone I wanted something different.
So my only choices was either the G2 or the HTC ONE and I got the G2 because Camera was a big issue for me and that Htc one had a ****ty camera, 4MP will always be 4MP so at cropping and zooming was not good and specially that hardware issue with purple ink pictures at low light.
Now then I dropped my G2 and cracked the screen. I was giving it a big thought about getting another phone instead of fixing mine but there were no other phones that satisfy me as the G2 so I fixed.
Now to your question..... Yes the S5 have a good camera specks and the new HTC ONE does too but LG still havent released the G3 and I'm sure it will be a killer. That new M8 sure looks good but still a 4MP so not for me.