I have been using this for a week. Performance is not an issue here, you get more than you paid in this respect. But the device has some flaws, mostly its the software what I felt.
Pros:
Performance is great. Its fluid and good for casual gaming.
Display is good with high ppi. Its amoled guys maybe not the best if compared with samsung models which costs at least double.
Camera is decent. With some tweaks and third party apps you can click good pics. Ya its not DSLR I domt expect wonders out of it.
Design + It can beat an iphone
Call quality is good.
Cons:
Battery not that great. Yes it can pull through entire day with moderate usage but on a heavy day you may have to plan for a boost.
Oxygen OS is buggy in some areas. Managing storages is a mess. SD card and OTG unmount may not work properly. Bit its livable. Waiting for the fix.
Warms up a bit. Its not heating abnormally, but yes its not cool device. Yes games and even heavy processing like panaroma warms up the device. But it cools fast too. Maybe its the material glass and metal which makes the heat notable.
Design is great but come to reality we use phones anywhere, in rough conditions also. And glass front and back is not ideal for that. You have to put on a cover which hides the beauty. Better get oneplus flip cover which is a great addition to the device instead of saving 300 with a ordinary one. Would be updating this space with further experience. Hope it goes well. : )