Just as you I have the Norge. Have heard the 320 with the Sono FS ... exquisite. Maybe, it was the synergy. Obviously, only a side-by-side comparison would be needed to come to any conclusion here.
I may be mistaken, but what little I can recollect ... 320 with Sono FS had precise highs, crystal clear mids and good bass. The Norge, I feel has a bit subdued highs, slightly mellow mids (in comparison), maybe slightly more bass .. though, a bit less tight to the 320.