Great way to keep your shotgun out of unauthorized hands but still available for rapid deployment. With a little practice, the vault can be opened very quickly without any key or RFID tag. Even in total darkness, the buttons are easy to feel, and the gun comes out easily. The build quality seems very good. The number of combinations is better than the other mechanical lock safes I've seen.
Although the lock is sturdy and secure, it is still valuable to conceal your weapon to avoid attracting the attention of thieves or curious kids. The ShotLock is small and can easily be mounted behind a curtain or door.
LockPickingLawyer on YouTube showed how the vault can be opened by inserting a steel wire through the small openings in the corners, and using it to move an internal latch. Kids are smart and also have access to YouTube, so I filled the openings with epoxy to mitigate the problem. I hope the manufacturer will address this soon, but be aware that alternative safes may have similar or worse vulnerabilities. Be sure to do some research on whatever you are considering.
One downside of the ShotLock is the tight fit around the shotgun's receiver. This prevents mounting a side saddle or shotgun card on the receiver for holding extra ammo. Also, I think it would be difficult or impossible to mount a red dot or ghost ring sight.