YES! I definitely think they should be noticeable. Otherwise I feel they are totally pointless to include in the game.
If people really want to keep their ui uncluttered, fine, add an option to disable them, but they should be displayed by default.
In guild wars 1, it’s one of the things that kept me motivated to keep playing for a long time. In WoW, same thing. It keeps you coming back to pursue something that can make your player unique. GW2 definitely needs more longer term achievable goals that players can shoot for. It adds to the “end game” answer of what to do when you’re out of content and don’t want to PVP.
I also think it’s an opportunity for ANet to offer in the cash shop. I might spend 200 gems on something interesting, especially if displaying the title adds aesthetics to the character beyond text.
Rift did it pretty awesome where it had separate prefix/suffix to add (E.g. Sir {name} the Senseless).
But as it is, I feel it’s a mostly useless feature because it’s so hidden.