I don't get Alter Time

There is such a terrible downside to Alter Time that I find it hard to use in my rotation. The downside is this: I end up being moved back to where I was a few seconds ago. I can certainly see why it's great for fire and frost mages, who can use it to double-proc, and I can see it has some great uses in PvP (for instance with blink), but as an arcane mage trying to raid, I usually don't want to be moved back to where I was standing a few seconds ago, because the only reason I would have moved in the first place is because there's burning oil or acid or something similarly nasty where I was previously standing. Raiding in this tier has required a fair bit of mobility, something arcane mages are not great at. When we do move it's because we are absolutely forced to by the void zone under us. Here's what happens to me every time I use Alter Time:

"Hey, I've got 4 stacks of Arcane Charge up! My next Arcane Blast will use up a lot of mana. Let's use Alter Time to have my cake and eat it."
- Cast Alter Time
- Start Casting Arcane Blast
Then a void zone opens up under my feet, my robes start to singe! Ouch! Get out of here fast! Run! Don't wait to complete that cast!
- Run away, little girl, run away
- Restart casting Arcane Blast from the comfort of solid fire-free ground
Alter Time resets
Doh! Back in the fire again!
- Run away, little girl, run away

So Alter Time usually ends up costing me time in most raid encounters, especially mobile ones. Arcane raiding mages, how do you benefit from Alter Time?