I recently purchased the H850 on Amazon for use on AT&T in the US. Short answer: it's a
terrific phone!
Background: my last phone was the LG G4, because I insisted on a phone with a removable battery and expandable memory (jumped ship from Samsung after the Galaxy S6 dropped them). I was very pleased with it, until it bootlooped into oblivion 1 month after the warranty expired

I swore off ever going with LG again, but I was resistant to going to a non-removable battery, which most flagship phones have now. So I labored on with my 5 year old HTC Vivid (lol) and Android 4.0.3 (lol), until I couldn't stand it anymore. Tempted by the V20, but very expensive. I was looking for a top-of-the-line phone with a removable battery, memory card, fingerprint reader and FM radio (very handy when riding on the train to work). Putting the parameters into Phonescoop, and the LG G5 was the only current phone on the list. Because only the international version has FM radio and is unlocked, I bought the H850. Was very pleased how easy it was to set up on AT&T's network.
Performance wide it's very speedy, the LG G4 is a step behind in comparison. The screen is slightly smaller, but it's very bright and sharp - my only complaint is that white is slightly bluish, as some reviews have noted. The metal construction is nice and solid, and it's lighter and easier to hold. Battery life so far is acceptable, getting up to 4 hours SOT with above-average use. But that's what a removable battery is for!

The wealth of hardware connectivity options is very reassuring - can't compensate for them with software. FM radio is great, as is having an IR blaster. Fingerprint scanner is very fast. They say the USB-C is only USB 2.0, but transfer times feel faster (~50MB/s vs <20MB for past phones). Compass, barometer, WiDi, it has it all.
Most importantly, the initial kinks seem to have been worked out - there is very little/no gap with the bottom module, and GPS is very reliable. Since this is an international phone there is
no manufacturer's warranty, so I'm using this phone without a net. I'm just hoping there won't be a bootloop issue on this one!
This is my first non-carrier phone in a long time, and the lack of bloatware is so refreshing! And knowing the bootloader can be unlocked and the phone rooted is important future-proofing insurance. I was tempted originally to get the H860 ($50 cheaper), but thanks to XDA I realized that no boot unlock solution has yet been found, and I've learned that unless it's expressly said a feature is supported, assume it won't be. I'll keep hoping that all other LG G5 owners will be freed eventually! :good: Once Nougat comes out I plan to unlock and root, and hopefully the developer community will port Android O in the future if LG no longer supports it.
It's amazing how far phones have come in just the last 5-6 years, but I am starting to get the sense that the pace of innovation may be slowing. Coupled with the end to carrier subsidies, and value is increasingly important. I have to admit, if I had to pay its original list price of ~$700, I probably wouldn't have. But LG's misfortune is my gain - at ~$450 it's comparable to the OnePlus 3 but with many superior features. In conclusion, I'm very satisfied - my only concern is reliability. But as long as it continues to work, I think this phone will last for a long time.