I recently switched from standard dia aluminium Pro Tapers to Oversize Carbon Pro tapers on my '97 Heckler. Similar rise and sweep and both mounted in decent stems (Race Face and U.S.E. respectively) of equal length and rise.
I can understand rationally the improvement in stiffness of the carbon OS set-up. Still I was blown away that it translates into noticeable different ride. I love the rock solid feel of the Oversized set-up and in the wake of this have converted my latest modern full sus ride as well.
For looks I still prefer the classic silver and gold ano set-up, for performance the oversize kit, no contest.
Enjoy!!