Insuring a C310 vs. Piper Seneca

I've got about 750 Total Time, 50 complex, 100 IFR. Private, IFR,
Commercially rated.

I have no multi time, but am about to go to a school to get it. They
estimate 10-12 hours in my log book when I finish my checkride. So,
in research mode I asked my agent to get me some rates on Senecas and
C310s in the $150-$175K range. She came back and said, even with an
instructor by my side, they won't insure me. Period. So, she asked
them at what hours would they insure me - here's what they gave her
(in the most vague of terms) -

Seneca - 100 hours multi with at least 50 in type
C310 - 50 hours multi, 10 in type

Huh?? Someone explain that one. I thought the 310 would be a higher
risk for them. No C/R props, flies faster and higher, etc. And, all
my time is in Pipers, including a lot in the Saratoga, so I'm familiar
with the cabin, panel, layout, etc. That probably means nothing,
though, except in my mind.

In looking in the $150-$175K range I'm finding I can get a reasonably
well equipped Seneca II(sometimes IIIs!) or a later model C310. I
like the 310 fuel capacity, speed, and sleek design.

I like the Seneca fuselage. I don't think either excel at hauling,
nor do I intend on filling it with 6 people often.

The C310 nonturbo models are still faster than the Senecas, which are
all turbo after the II model. That's more maintenance.

What are your thoughts on the insurance and comparing the apple to the
orange?