500 Fan,
The D model is preferred due to lower weight, smaller instrument panel (better visibility.)
The 530FF generally is too expensive for the advantage it offers. A 500D with an R engine would be a much better alternative.
Companies such as Haverfield, Air 2, etc. generally make due with what they have. Fleets are a mix of D's and E's usually due to what is available for the right price when a company is in the market to expand the fleet.
MD was talking a few years ago about building a G model. Essentially an E model express built for the utility market. Don't know what happened to that idea. What they need is a light D model with a cut down instrument panel like the old 269A IMHO. Maybe with a nice digital engine display package. Then again maybe not as that might cut down on the pilot's "finessing" the most out of the old girl.
I don't know, Tilton doesn't seem to recognize the unique mission role of the 500 and the fact that there really isn't anything out there that can replace it in many applications (powerline maintenance being one.) Then again, she also seemed oblivious to the fact that military folks, hard partying aside are quite conservative by nature and might be put off by someone who brags openly about using sexuality to get what she wants in the business world
Not to say i don't like her. She seems quite bright but oblivious to the potential captive market right in front of her.
[Steps off soapbox
]