Don't know about you folks, but I get the distinct impression that the argument is decidedly in favour of synthetic, not only as a viable alternative, but indeed a better one. 

My hat is in the synthetic ring.  Changed to this stuff when I replaced my clutch plates.
1. Soak corks in synthetic 2 days
2. Drain oil and replace filter
3. Pour in the synthetic
500 smoother-shifting miles later, I did a second oil change and new filter. ..and WOW!  the oil was still fresh looking.
Here's the commercial( read from label on back of jug)....
"
High Performance Engine & Transmission Lubricant
AMSOIL Advanced Synthetic 10W-40 Motorcycle Oil is engineered for maximum performance in 4-stroke engines and motorcycle transmissions, both two-and four-stroke.  It is wet clutch compatible and features better heat resistance and wear protection than other motorcycle oils.  AMSOIL Synthetic 10W-40 Motorcycle Oil is 
Shear Stable. It stops viscosity breakdown (loss), protects gears and meets SAE 80W/90, API GL-1 gear oil requirements.  
AMSOIL Synthetic 10W-40 Motorcycle Oil is recommended for Honda, Kawasaki, Yamaha, Suzuki, BMW, Husqvarna, KTM, and other motorcycles where 10W-40 or 80W/90, API GL-1 is used in engines or transmissions.  Not recommended for shaft drive hypoid gears.
CAUTION: Continuous contact with 
used oil has caused skin cancer in lab testing.
-  No friction modifiers for outstanding wet clutch performance
-  Extra anti-wear additives for long equipment life
-  Promotes cooler operation
-  Prevents foam in high RPM engines
-  Protects against rust and corrosion during storage
"