Castillo was much more technically sound than Ortiz. Castillo also used A LOT of head movement when he would work his way inside (dipped his head down low and bobbed side to side), something ortiz doesn't do. In addition he worked the body very well and he had a fantastic chin at that time. He also had 50 fights going into the floyd fight and had been in the ring with better opponents.
If you re-watch the Berto fight, Ortiz lunges in with shots from the outside, that's basically how he gets his shots off and to get inside. that, IMO, spells absolute disaster against a technician like floyd. You can't lunge in against Floyd or you'll get Ricky Hatton'd. You need to either work your way in with a STRONG jab (not a lazy, half-assed jab like mosley used) or do what castillo did and bob and weave that head around unpredictably. Ortiz does neither.
That's why I'm not betting on him! Too inexperienced and doesn't have the right skill sets to beat floyd (strong jab to get inside, head movement). Lamont Peterson was giving Ortiz some problems too and I use that as an indicator. Watch the mid-late rounds of that fight and watch how easily at times he was able to counter ortiz and set traps.