A D or E model make for a fast ride.
I flew an E on a corporate gig and our passengers liked it
When I mentioned to the owner about how cramped the back seats were….he just laughed and he could care less as he did not intend to ride in the rear ever.
But he did…we had a Regional manager that was a really big guy….had to get a seat belt extender to fit him.
He could not fit into rear at all…..thus the Boss Fellah would ride in the rear on the flights the big guy did.
We positioned gravity feed elevated fuel tanks at each of our sawmills and used good filters and Number1 Clear Diesel to eliminate the need for n Aux Tank in the Aircraft. That gave us the ability to adjust the fuel load when working out of the mountain locations in the Summer months.
The one thing that sold me on the D over the C model was the Vne limit.
In cruise you could maintain cruise power and lower the nose and peg the Vne speed by adjusting the pitch angle of the aircraft…..but in the C it would require a collective change.
The only complete engine failure I experienced on a single engine helicopter was on a D model in Alaska.
I was quite lucky and landed without damage.