CX Bike to replace a dolomite

Prowlus

Hi all . This is the first time i'm posting here cause I'm not much into the roadie scene until recently in 2012 when I purchased my first road bike namely a pinnacle dolomite 3(?)from Evans and now its getting a little old and worn out over the times and i'm thinking on replacing it with something newer and possibly more flexible .
I'm considering a CX bike like a boardman CX comp, a Jamis Nova, Roux Conquest 2300 or a Norco Threshold A3 because , I can switch to emergency offroad when necessary but still retain the speed and agility of my old racer .
Which spec would you recommend out of the three?