When should I use a swapper?

I've been playing Heat Signature for a few hours now, and I have yet to find a good use for the swapper items in the game. Under what scenarios are swappers useful? They seem like a neat idea, but ultimately don't seem necessary.

Swappers are awesome. The main reason is that they're the only permanent teleporter that can take you through locked doors.

The simplest use is swapping with a patrolling guard on the other side of a door. Swap with them and you're on the other side with one fewer guard to worry about (the guard you targeted will just panic). As Murgatroid said, this is particularly effective vs groups of two guards.

You can also use the swapper to assassinate or capture a target. Use a visitor to teleport yourself outside the ship then use a swapper- that target is floating in space. Use a glitch trap and stand on it for the same effect- when you swap the target ends up on the trap and wherever you want them to be.

This doesn't just work on enemies. You can also move rescue targets this way. Swap with the victim and you can put them somewhere safe, while you escape from their prison. You can even put them outside the ship using the above method and rescue them. This usually works.

The simplest scenario when a swapper is useful is when there are two guards remaining in a group. You can swap with one and immediately kill the other with a quiet weapon. The guard you swapped with will simply stand around confused, and you can return and kill him at your leisure. Essentially, you are using it to jump close to the guard to ensure that they are in melee range before they have a chance to raise the alarm. You can multiply the effect with a Slipstream. If you activate a slipstream then immediately swap with one guard in a group, you can easily kill several before any of them can attack you or raise the alarm.