I had several opportunities to sit down and play the Ibanez Xiphos and it is indeed a well made guitar and far heavier then the Jackson. Alder bodies never did a thing for me regarding Jackson's and I have owned several very pricey one's. They never stayed in the house long. Sure they are well built but every Jackson I have ever owned or played had a "cheap" feel to it due to the flyweight
The Xiphos sounded warm and massive and the few I played had a very cool flip-flop paint job
For the money, IMO the Ibanez is a better guitar but you may feel different once you actually do a side by side comparison. Both guitars play extremely nice, I give the nod to the Ibanez for the faster and slimmer neck and warmness of sound
Either way, you can't go wrong with either in that price range