I've been looking at these lately as well.
I don't like the Stack-on, where it requires a key. I would rather have some kind of electronic or push-button mechanical lock, such that I could open the thing any time. The Closet Vault model is good in this regard. But I don't like how that one extends outward from the wall. I'd like something that I can put a hinged mirror over to conceal as well, and I think that one is just too big for that.
I like the looks of
this one from Stealth Wall as it looks more natural and already has the mirror built in, but again it requires a key. And it is really just for concealment, and appears less secure than the Stack-on model. The locking mechanism appears to be the same type of child-proof locks I have on some of my bathroom cabinets. It will keep small children out, but a strong tug will defeat it.
So ideally, I'd like to find something that's set up like the Stealth Wall, and locks like the Closet Vault.