I think there is a difference in something that makes things easier and something that makes things trivial. Then again the source skills are so powerful that this might not matter what so ever in the long run.
At early levels it's pretty powerful to Port an enemy onto his aly, do damage to both, and make him miss a full turn just to get back to you, and possibly be allowed poisoned or burning. At higher levels when you're going twice in a row or dealing 500% damage with source it might be more of a loss using AP to teleport someone than a gain.
