Gordon, if you were just starting out with no tools and you just wanted to turn pens I would say go ahead with the carbide, but seeing as you already have your own standard lathe tools why not keep on with them?
I started off with carbide and am still using them, and like them, but then I only am turning pens, generally.
I think that there is no difference in the finishing. ( others may disagree ! )
I finish my pens using a shearing cut with a radiused square carbide.
Alan