I’m not especially fond of cap rings. Whether they are single and slender or multiple in patterns such as thin/medium/thin, they’re just things to help to keep the cap lip from splitting. I would make an exception for the ones that are genuinely decorative or are a feature, like the Swan Visofil pierced cap bands or the large metal bands of the Sheaffer Triumph 1250 or Waterman Taperite. Otherwise I would prefer that they made stronger cap lips.
The Conway Stewart 479 is an excellent example of a pen with no cap rings. I’ve had many of them and none has had a crack in the lip. This is because the lip is a fraction thicker than those with cap rings. It seems an altogether better design as cap rings don’t actually prevent cracking of the cap lip, as we have come to know all too well.
The 479 was a very popular pen and it had a long period of production. It came in some outstanding colours, too, like this deep plum and black marble. It’s a very rich pattern, all the better for being uninterrupted across the cap and barrel by cap rings. This particular example is enhanced by having a quite flexible stub nib.