I don't think comparing model performance for the last storm has any bearing on what to expect from guidance on this storm. They are two totally different setups. In retrospect though, all guidance really struggled with the last storm. Every model, every run, was yielding a totally different look and evolution of the 500mb energy but given that regime that should be expected.
Also, when it comes to potential phasing events its all about timing. The slightest difference in the timing of the phase can mean a SLP of weak sauce with nothing or a full fledged nor'easter.
Even on the Euro there is more room for the northern stream to dig given the jet streak associated with the trough but subtle differences can result in big changes to the sfc output.