I think the Interestate tank is a great looking tank for a large capacity tank. I also like the look of the Roadster tank, however a friend has one of those on 750 and barely makes it to the town of Hope (90 miles) from home in Vancouver before needing to refuel. This can be quite annoying when on long trips where we often cover 500 or more miles in a day.
The stock Vincent tank is also very pretty with an annoyingly short range, better than my friend's Roadster, but still only about 150 miles. Some Vincent owners fit large capacity tanks, but all of the designs I have seen to date are quite hideous. By comparison the Norton Interstate tank is quite lovely. Too bad it wouldn't fit on the Vincent.
The side panels are just fine too, although I do see some on the earlier Commandos which are rather ungainly.
All in the eye of the beholder I guess.