Inbalance.
It was absolutely true and I do not like being called a liar. From the B250 POH:
F250 TAS 301
F280 TAS 307
F310 TAS 301
So the 300 knots is at F310 with the low burn.
If one wishes to cruise at max range power, 240 kts TAS at 12000lb, F350 you will burn 380 lb/hr. So 20 kts less than the PC12 but similar fuel burn. And two engines. This will increase the payload.
At 20 deg C MTOW the LDR is 1200 feet. Perhaps you are getting metres and feet mixed up?
If you buy the high float gear doors then there is no speed penalty.
Pilatus requires maintenance every 100 hours plus annually. Beech is every 200 hours only.
Insurance may be cheaper, but some individuals personal or business insurance requires them to travel in a twin.
I said previously the PC12 is a smart machine, and it has it's uses. However at the end of the day it's only a single so I guess it depends on how safety orientated you are.
Have a nice Sunday