All you can really do is try out the new class. I have been trying to create a Marauder/Archanist throughout the game, and found that doing the main line quests as both make the levelling a heck of a lot less painful.

I don't know what to answer with if to create a new character. You might start off in a new area, and if you are soloing that's great, but if you are part of a group I would stick with the same character.