The things are rather interesting and enjoy popping them out once in a while, but they seem to be almost completely infeasible to be worth a device slot on any other character aside from tactical characters because of tactical initiative which helps me get it under 3 mins per use rather than 10.
I think it would be real nice to have it more inline with the cooldowns that the shard of possiblities and ophidian cane have, around 3 or 5 mins instead of 10 to make it semi practical for non tactical characters to use. 10 mins is just an eternity for anything.
Danger of using one: you can sometimes get hella unlucky and spawn a Deadly Phantasm (Devidian Boss) while using it. (I have had this horrible thing happen once on an EGSTF. My team. Was pissed. The Borg weren't much happier though, the Phantasm tore them up pretty hard too until the Elite Tac Drone got annoyed and slaughtered it)
But other than that, it's an interesting device (despite being unable to move it).
It is said the best weapon is one that is never fired. I disagree. The best weapon is one you only have to fire... once.
that "danger" is in fact one of the things I love most about it! it's pretty amusing getting devidians and out of time starfleet or klingon personnel in strange places, I won't ever forget the time I had a phantasm attack tholians on nukara surface for me hehe, it was on fire the whole time too! But it's super rare any case that it happens, and of course the ultra long cooldown makes it even more so.