Thinking of getting one since its release in my country a few days back
This phone has nothing outstanding. It's not a top-of-line phone and has no innovative features by the company. The company, which is small, just puts together the features of other phone manufacturers and sells it. 2 models are released per year. The 6T model will be coming soon in the 3rd to 4th quarter of this year.
If you check the net this chinese-made phone maker in the past had its fair share of spyware issues but for them its over now unlike Xiaomi, Oppo, Huawei etc
CONS
1) Comes with a notch - follows the iPhone
2) No microSD card slot
3) Not certified to be water resistant
4) Not so great cameras
5) Not so impressive battery life
6) Screen not too bright in strong sunlight
7) Single speaker
8) No wireless charging
9) No HDR support
10) No in-screen fingerprint sensor
11) FHD screen only
PROS
1) It's as clean as a pure android phone (like the Google Pixel) with its Oxygen UI over android Oreo 8.1
2) No FB pre-installed. Other phones which do NOT have FB pre-installed include Google Pixel, Motorola, Huawei Honor series.
Google Pixel - not too keen since it's by Google
HTC - bought over by Google so not so keen on it as well
Moto - owned by Lenovo, another popular chinese company with spyware issues and, also, not using latest SD processor
Huawei Honor - not using SD processor but Hisilicon Kirin processor
3) Reasonably priced phone if you don't mind the CONS
4) Uses latest SD 845 and runs at Gigabit LTE speed
5) Comes with 8GB RAM and 128/256 GB storage
6) Fast in operation
7) Screen is AMOLED which beats many LCD competitors
Watch this link on something you may not know about its OIS and EIS stabilization
Its forum also spells the problems faced by users
OnePlus 6: Questions & Answers.
If you don't have the urgency to buy you can wait a bit longer for the 6T model which, hopefully, will solve the CONS listed but definitely will be priced higher. No matter how it'll still be priced lower than SAMSUNG and iPhone top-of-line models