Kaizen,
Keep in mind this is just my opinion and what I've experienced.
Less caster seems to make the car more aggressive during initial steering input i.e. more twitchy feeling. It also seems to give less overall steering, especially mid-corner and corner exit.
However, many people are finding with the Xray that the zero degree blocks (which are aluminum) are giving them more steering all around due to the fact they flex much less than the composite C- hubs.