I upgraded to the OnePlus 11 from my Samsung Galaxy Note 9. I ordered the "good condition," knowing I'd be putting it in a case, and any cosmetic blemishes would be covered. I was delighted to get my phone and not be able to find any blemishes whatsoever. I have no idea what would separate this device from an "excellent condition" device. I have yet to find any flaws.
The eternal green is marketed as being smooth in hand, and it is very smooth indeed. My wife immediately commented on how slick it is. But my plan from the outset was to put it in a case, so the texture is not an issue. I even found a clear case, so I still get to enjoy that awesome green color.
The fast charging is excellent. Battery life is great. Even with no battery saving features enabled, I am easily getting a solid 24 hours of light to moderate use. I'll throw it on the charger while getting ready in the morning and have plenty of juice at the end of the day.
I have been impressed with the cameras. I've seen mixed reviews on these cameras, but I'm guessing those reviewers were not coming from a 7-year-old device. I have been very pleased with the camera array. The zoom wheel is a nice interface.
The alert slider is fantastic. I'm using it way more than I expected. I do wish it were customizable. Even just to remap which position gives which ringer option. I rarely ever have my phone on full ring, so having the silent and vibrate at the outside and the ring in the middle would be my preference. But it is easy to use as it comes.
This is my first OnePlus phone, and I am very pleased with it, and I think I got a great deal from BackMarket.