I have a Motobecane Fantom Cross Outlaw (my commuter bike, running Specialized Borough CX Armadillo Elite tires) and a TriCross Comp (my cross bike). While the Fantom is a solid quality bike, it's extremely stiff and fatiguing to ride compared to the TriCross (and Secteur). The TriCross has damping and compliance built into the frame and fork that simply isn't there with the Fantom.

If your bike shop was recommending the Secteur, Synapse, and TriCross, they've probably assessed your needs as being toward the plusher-riding end of the frame spectrum so think about what you really want in the ride quality of the bike.