A lot of difference in the handling of the pattern. Gfs and Ukmet digging a troff along the southern apps, other models, not so much. Cmc and ecmwf AI have a cutoff low over TX/OK
The 6z Icon keeps the track inland through PA NY and NE. This would mean a lot more impact for the Mid Atlantic and New England.
Also note that both the gfs and Icon both handle the NS differently on their 6z runs and show an amped up troff over the great lakes, which allows for this track.
Results in a much stronger landfall.
Edit: Actually only slightly stronger. But further offshore track should in theory give it a lot more time to reorganize.