The SV500 is a nice, well made device that serves its purpose without fanfare. This one is the keypad version, not the biometric type.
The keypad works well, but is limited to only four buttons. You can press two (or maybe more) buttons at the same time, but I have found I am not as consistent, or error free, when I try to press more than one button at a time. This could be a problem in a panic situation. An extra two buttons on the keypad would give me more programming options, without adding too much complexity.
Also, you have to be careful not to press the next button in sequence too quickly, for instance in a double-tap of the same button, such as 2,2. If the second press is too fast, you'll have problems.
Installation if fairly straight-forward. There are four mounting holes for the bracket. You'll want to try to hit a stud (or something solid) with at least two screws. Use long screws, and drill out pilot holes first. The other two screws can be attached with heavy-duty sheet rock anchors.
Programming the key pad, and cancelling the beep sounds when keys are pressed, is easy enough. The instructions are fairly good, as I remember.
I wish it had a space on the inside for an extra magazine, but it does not, at least not that I could find. So, we're left with leaving a magazine on the top of the safe, or attaching a mag pouch to the side. I guess the idea is just to grab your gun and go.
The price seems a little steep, but I have not found...