EDIT: I reread snapshot and realized that gunner won't let you attack again in the activation phase. Please ignore this noob's post.

In general, you need high PS TIE Phantoms in order to shoot first and proc Advanced Cloaking Device before taking fire so VI is always an auto-include. I'm thinking Snap Shot could be used to give your Phantom a cloak token before ever getting to the combat phase.

It gets even scarier when you add Gunner + FCS.

For example:

Echo (30) + Snap Shot (2) + FCS (2) + Gunner (5) + ACD (4) = 43 pts

Against lower PS ships, you can in the traditional Whisper style while having the added Echo maneuverability, while against high PS aces, you try to figure out where they're going and make sure you'll have a range 1 shot after their maneuver, this is easier due to Echo's slippery decloaks. This gives you the ability to get your 2-dice Snap Shot off and then, if that misses (which it probably will), you get your 5-dice primary (with modifiers - at least a target lock due to FCS) against them. Furthermore, you'll get to cloak after either attack (snap or gunner) and before the attack phase thereby nullifying the downside of being PS6. Moving into range 1 would be death for any ace unless they get lucky enough to not proc Gunner.

I don't know if it would work in practice, but the idea is kind of interesting, thoughts?

As you are cloaked you wouldn't be able to use your powerful normal attack in the combat phase.