I've recently owned both, SS9+ for a few years (about 8k miles) and HD LW for a year plus (about 2k miles).
Comparisons:
Drivetrain: LW A+, fantastic and quiet. E: A-, drivetrain is almost as nice but has that whine. YMMV regarding that sound. The E chain also is noisier.
Handling: LW B+ super stable but not nimble. E: A once moving, but only A- overall because it's top heavy and wants to be dropped at super slow speeds
Range: compared to what? A gas moto, they both lose. Compared to each other, the LW is more efficient per kWh, but the E has bigger batteries and longer range
Build quality: A for both but HD is a bit better, especially switch gear.
Charging ease: HD: C- (DC charging is slow, AC is really slow), E: B-, DC charging is slow but better than HD, ditto AC. Also some DC charger compatiblilty issues .
Usability as a tourer or commuter: HD: D, they simply ignored luggage, and the geometry favors interstate stability, not slower speed agility. E: C+. But the Experia looks better and may raise that grade to A.
Fun to ride: this is subjective, but both get an A+ in my book.
Dealer availability: pretty slim for both, alas.
Riding position: this also is subjective. LW riding position - leaning forward and stretched out made my shoulders hurt, but that's just me.
Styling is subjective. I like them both.
Other stuff: LW mirrors are a joke. Both interfaces could be better, e.g the E cruise control button should be something you can reach with both hands on the bars.
edit: additional thoughts:
both weigh almost exactly the same.
HD lower seat and lower center of gravity are nice for a commuter. But no grip heaters and no reverse gear.
The DC charger compatibility issues I've had with the Energica have been common, and at chargers that worked for the HD. But based on a later post may be confined to the US.