I've been considering a G3 to replace my own S3 for maybe two months now. The LG Flex also got a look in, although it's really a competitor to the Note phablet.
Based on their recent offerings, LG's next generation after this seems likely to be completely dominant. The technology in the Flex and G3 is just amazing. And just as importantly, their software has gone from bottom to top of the class. Frankly, everything else from competing manufacturers is pretty boring.
On the flip side, I'm pretty sure I don't need insane pixels-per-inch numbers. I've yet to read a review where someone claimed that the extra resolution was clearly visible - not surprising given the well-established limits of human eyesight. And despite my significant respect for the G3 focusing system (claimed to be "laser" but not), a reality check shows that the Samsung S5 is very nearly as fast (although not in poor light, presumably). On top of that, the screen did not fare well on GSM Arena's sunlight test (although it did on another review I read).
But if you want the current pinnacle of smartphone engineering, the G3 is definitely IT.