My Aiptasia experience thus far:
First, I tried Aiptasia X. It worked, but the Aiptasia seem to come back ten fold.
Second, I added 10 Berghia Nudibranch to a 65g display with no known Berghia predators. After adding them to the tank, I never saw them again, and the Aiptasia remains.
Third, I added 3 Peppermint Shrimp to the display. Since adding them to the tank, I have only seen glimpses of one of them. It has been several months, and the Aiptasia still remains.
Fourth, I purchased a Filefish just this last weekend. It's healthy and happy, and on day 2. So far, the Aiptasia still remains.
* SigH *