I know some people are fanboys, but I think that label gets thrown around a lot more than it should. If LG had knocked it out of the part with a brilliantly designed device with a smooth, powerful UI, great cameras, and a fantastic build, does anyone really think there would be as much disappointment as there has been with the G5? Of course not - people would flock to that device. Sure, you'd still get the few hard-core fanboys complaining about some trivial issue with the G5, but that's not what we have here. There are very legitimate reasons to be disappointed with the G5, especially after LG did such a great job with the V10.
Personally, I'm platform and OEM-agnostic. I have an iPhone 6s Plus that I use for work, and a Samsung Galaxy S7 Edge that is my personal device. I love both equally, and sometimes swap SIMs between them, depending on my mood. However, they are very different devices - OS, screen technology, design philosophy, open vs closed ecosystem. Big differences between the two. But there are elements that they have in common that draws people to them - - fantastic build quality, great cameras, great battery life, smooth operation, great-looking screens. Samsung and Apple take very different roads to get there, but they both arrive at the same location with regards to getting the important things right.
This is where the G5 fails. It got some of those core elements right - cameras are great, the screen looks great, and operation is smooth. However, they failed miserably with one of those important core elements: build quality and fit/finish. Perhaps the issue is with the first batches of the G5 coming off the assembly line, but even so, it's still looks bad compared to Apple and Samsung, who seem to have better, more consistent quality control and the ability for the first devices coming out of the factory to look as good as the most recent ones coming off the assembly line. LG has to fix this, and gain this consistency of QC.
I returned my G5, but I have to admit that there are elements of the device I really like - the wide-angle camera is really cool to have (though I wish it were at least 12MP instead of 8MP). And the screen, despite being an LCD, is really nice to look at it in most situations (still not as good as Apple and Samsung in direct sunlight). Battery life seemed OK. But the thing that killed it for me was the inconsistent quality control. The G5 felt cheap, and the uneven gap at the bottom where the battery module is connected was too much to just ignore. Perhaps I might get one again from a future batch, because I do like the other elements enough to still want one. But right now, it's hard to recommend the G5 over other devices like the S7/Edge. I hope LG learns from this, and doesn't repeat these mistakes in the future.