Ducati 1000 vs. Buell 1000
The Ducatis ability to rev another 1,500 rpm more than the Buell, gives the slight advantage of a wider usable RPM range (1,500rpm - 9,000rpm, compared to the Buell's 1,500 - 7,500rpm) and coupled with its six-speed gearbox, allows the Ducati to use closer and shorter gearing. (Note: the Ducati charts 2,000rpm start is due to operator error or a cold engine at fast idle also operator error)
Now, before all you street-oriented low-rpm torque advocates start screaming; take a close look at these dyno charts, not only does the Ducati make more torque everywhere, it carries a higher output in a much smoother fashion all the way through and beyond the Buell's rev limiter.
Aside from overall physical F-to-R length and valve adjustment issues, the Ducati engine appears to be superior to the Buells in almost every way... throttle response, tractability, power, torque, usable rev range, etc. Actual fuel efficiency is unknown, but probably quite similar to each other. Keep in mind, these are both perfectly-good engines and just because the Ducati has better dynamic performance, doesnt mean the Buell is useless. On the contrary, the XB-9sx is a barrel of monkeys. Itd just be a bigger
barrel if the Ducatis motor could fit in the Buells chassis.
Unfortunately, I don't have access to the MO dyno anymore, so I can't create a custom overlay chart of the two motors. However, here are the separate charts from the same dyno on different days. The vagaries of density altitude may play a slight factor, so figure +- 2hp for each engine. Ducati DS1000 Dynochart
vs. Buell 984 Dynochart