Howdy Thud, welcome.
Knobbies, give ya a sort of buzzing vibration. Fat, street tires are smoother as are the 4 stroke engines. But the 4 smokes are larger and not as purty. I think a better ride but have both and depends on the day and mood sort of deal.
Best bet is hook up with some one local and ride one. But they are addicting and you will need 3. The one your ridding. The one your building and the one your planning. LOL