This phone still impresses in 2024. It still feels every bit a premium flagship phone that hasn't really been left behing even by 2024 flagships. The 10x optical zoom with up to 100x hybrid zoom sounds like a gimmick, and it really would be if not for some stellar assistance to get things in focus from the phone. Shots of the moon are incredible, along with many other applications. Also this phone is still being supported by Samsung with updates that are likely to last another year or 2. Performance is still great. The screen is also still elite with only top end full daylight brightness falling short of the elite 2024 models. The only major demerit for an S21 Ultra in 2024 is the battery life, it hasn't aged well and seems to be 60% or so of the current S24 Ultra. This is a combo of degradation of the old along with advances on the new.

As far as the specimen received from Best Buy, it didn't disappoint. The screen and body looked new, the only issue was a finicky, but usable charging port.

Overall the phone "worked" at its basic functions but i ended up returning it.

Listening to anything would have weird feedback randomly, a low, long beeping sound for some reason. It was not super loud or super frequent, but it kept happening.

The phone itself was not flat. when you put it on a desk or something it would wobble because 2 corners were higher than the other 2, meaning the frame must have been bent at some point.

Sometimes the battery seemed to drain faster than expected, since the listing claims they all had new batteries in them.

it also had a hard time connecting to some public wifi networks where they have you click a link to sign in to the wifi. My old phone always signed in just fine, this phone kept going in a loop. I had both phones at the same time so i know it was not a network issue.

overall it was just a bunch of little things that made me return the phone because i doubted the phone would be good for several years. I know i bought it refurbished and that can be luck of the draw, but the one i got this time was closer to a bad phone than a good one. I probably could have survived if i kept it, but it would have been an inconvenient phone to try to use.

My understanding was the S21 Ultra phone was like new quality or from a restocked opened box. However, the back panels on the phone had hairline cracks. The screen display periodically gets distorted when scrolling in various apps and internet browsers. I could overlook these two issues. Unfortunately, the battery life is significantly less than my 4 year old S10 which is extremely annoying. The phone does not last a day without needing a charge. I use power saving mode and this still does not allow for a full day use. This is phone is not "like new" as described in the listing.

The model sent to me was identical to the phone I was replacing. However, this one was refurbished, which didn't bother me at first. When I got the phone, it had a deep scratch on the verge of a crack %26 after spending 2 days with my carrier trying to get it set up, they said it was either not fully unlocked due to not being able to reset the system to specific settings inputted or it was a defective phone. I think it is a combination of both. I ended up returning the phone %26 bought a new, fully unlocked phone instead. That way, I have a much better shot of not having issues from the beginning. The quality was less than expected %26 ended up being useless. It was a waste of time, so I wouldn't bother to buy this model again.