Depends on how our FA period goes and what our draft plan is. If we're looking at players like Michael Brewster and Philip Blake in the later rounds for center then I would grab Michael Floyd, but if there's another receiver they like who can be had in a later round then perhaps DeCastro is the way to go. If it's my choice I go after Floyd, we need a receiver more then an interior lineman. If we got Jackson or Bowe in FA I would be more willing to get DeCastro since our WR position is taken care of. I would still want a WR in the early rounds even with Bowe or Jackson on the team.
If it's DeCastro or Konz I'll take DeCastro all day. Both should be great lineman but DeCastro, as you said, is an elite talent. Something that you don't see every year. All three are players who the Bears could use and look like can be perennial Pro-Bowlers.