OK here is my quick summary..
V-Twins are on their way out in racing..They are inherently inferior to I-4s and V-4s. That said the Buell V-Twin is much more inferior to Ducati V-Twins. Just to muddy the water but back when Twins had a 250cc advantage to I-4s in World and AMA World superbike. Honda built a V-Twin, RC-51, which was superior to Ducatis. Colin Edwards on the RC beat Bayliss on a Ducati. In addition the Honda engines lasted a lot longer..