[X Style (Pure) Q&A, Help & Troubleshooting] jetman36:
I would personally pick the Moto X pure (partly because its what i own).

Moto X pure Pros:

Unlocked- your not stuck with AT&T if you get the pure because it also works on just about all US carriers.

Almost Pure Android- Aside from the couple of additions from Motorola this phone as close to a nexus without it being one.

Big 5.7in QHD Display- it has a very nice 2560x1440( 4x 720p HD) display crammed into 5.7in so its plenty sharp.

MicroSD Card slot- Supports up to 128gb MicroSD cards (official max MicroSD card capacity)

Stereo Front facing speakers- true stereo speakers that face you and get plenty loud.

Customization- Moto maker, colors, woods, leathers, and bamboo (EG. grass not wood) plus accents choices and more. lets you finally get a phone that's a color you want...Mostly.

CHEAP, sort of- At $399 for a base model 16gb, its a great value! $449 for the 32gb and $499 for the 64gb versions. Add $25 if you want a wood (or bamboo) or leather back. Rear engravings don't cost extra.

TURBO CHARGER- comes with a 25w Motorola Turbo charger that can bring your phone from dead to full in about an hour and 15 mins. great when you need a quick top off while you change for a night out after work!

Moto X Pure Cons:

Its BIG- at 5.7in, even with the very slim bezels its still a big phone, not easy to use one handed if you have small hands.

Battery life- the big 3000mah battery is offset with that big QHD display so its not going to be great, just average.

Almost pure Android- you wont be getting any of the neat features that LG bakes into there version of android like mini apps, dual apps, the're AMAZING camera app.

LG G4 Pros:

5.5in QHD Display- Not as big as the moto X pure but still a great, sharp display but a bit easier to manage than the bigger Moto X Pure.

Swappable battery- battery go dead while out and about? just pop in a fresh 3000mah power cell from the bag and your back in business!

LG tweaks- Dual apps, IR blaster, great camera software customizble quick settings. all good features Stock android doesn't have...yet.

MicroSD card support- I don't think I need to explain this one again. ;)

LG G4 Cons:

Locked phone- Cant easily leave AT&T and take the phone with you. Might be able to use on T-Mobile but you out of luck if you want to move to sprint or Verizon.

LG tweaks- LG has useful additions but that also means it could take longer to get updates to newer versions of android because they have to modify android just to put those cool tweaks in there.

Single rear speaker- It might get loud but its still just one and its still facing away from you.

Price?- The 32gb LG G4 with plastic back is $135 more than the 32gb Moto X pure plastic(rubber?). if you go with leather on the LG G4 its $150 more than a 32gb Moto X Pure with leather (or wood/bamboo)

Those are all of the main pros and cons to each phone that I can think off right now. I used to have the LG G3 before and my buddy let me play with his LG G4 and its not all that different from the G3 before it so thats where some of my information is based off of for the LG G4.

Prices showen are from Motorolas website and AT&T website for LG G4 prices.

Hope this helps.