Here there is a lot of discussion. The Spigen tempered glass is simply flawless and compared to other screen protectors I have used, it may have the best performance in not easily creating fingerprints. If I were to rate the tempered glass on its own, I would give it 5 stars.

However, the product includes the ALIGNmaster which in my case I did not find particularly useful. The full-face screen protectors have a black line around the edges. This line is very marginal on all screen protectors and if it is not properly aligned, you lose half a millimeter of the screen. While the ALIGNmaster may seem like it has aligned the glass correctly, it can easily be off by half a millimeter to the left or right. This happens because the margins of the ALIGNmaster are sharp edges, while the glass has curved edges, and the sharp edge can sit even half of a millimeter on top of the glass. This can be noticed when the glass is placed. It is fine on one end, but the sharp edge presses against the glass on the other end. Not visually, but when pressing the ALIGNmaster, it "clicks" on the glass.

In everyday use, this may not be noticeable, but in my case, I noticed that it was not 100% centered. With a Spigen case, you could see that one side had more gap in the glass. It was not off on any side, but it was closer on one side.

In the end, I broke one glass because I thought I was doing something wrong. I put the second one and the same thing happened. Finally, I placed the glass without the ALIGNmaster and it fit perfectly.

Update: I tried it on another iPhone 14 Pro Max with a new ALIGNmaster and the same thing happened. In the end, I corrected the placement without using the ALIGNmaster.

Result: Compulsive people like me are better off getting a plain Spigen glass without the ALIGNmaster.