I tested two of these...
I just tested out the RG3EX yesterday at Guitar Center... They had three at that particular store, all with quilt tops: transparent red, trans orange, and trans black.
The red one looked amazing... I tried that one (with the EMG designed pickups) and it felt quite nice. The neck felt a bit thicker and flatter than my three Ibanez electrics (two RGs and one S), but it didn't feel huge or cumbersome to me. Not to say that Rich's comments above are inaccurate, but perhaps he is used to the ultra-thin Wizard necks, or has higher priced Ibanez guitars that I do... (Am I right, Rich?)
The setup on the red one was great, and the pickups were quite hot in that the pinch harmonics came out easily, and sounded quite awesome... I later tried the black one, but that one wasn't set up as nicely. The action was higher, and somehow, the overall feel of it didn't compare to the first RG3EX I had tested. I think I will go back to Guitar Center today to check out the guitar again... I'm seriously considering picking one up for $400... If anyone knows more about this new RG, please let us all know more!