Well, very few people have had a chance to try the D-Activators or any Ibanez models so it's doubtful that anyone will be able to give advice. But anyway, it's not about what other people tell you is a good or bad pickup, it's what your ears say. Only you can decide whether a pickup is right for you, and you'll feel happiest in your guitar-playing life if you follow your ears.
However I'm sure as the first person gets a Xiphos they'll leave some feedback. I personally can't wait, as if the D-Activators are good I might try getting hold of some.