I'd go with the AIG without hesitation.

In the closing days Sept 2000 I had an accident in my 360 that totaled the
aircraft.  I had AIG insurance at the time.  My experience with AIG was that
they were thoroughly professional and timely with their analysis of the
accident.  By mid -November they had paid the claim.  I think that they
would have completed the process sooner but they were delayed by the
collection of quotes to repair the damage.  Being a homebuilt, they did not
have the network of repair facilities to quote on repairing a Lancair.  Even
given that, they quickly determined that the accident was a total loss and
the check arrived within 45 days of the accident.  They even paid me "rent"
to keep the aircraft in my hangar awaiting the auction.  The airplane was
gone from the hangar by the first week of January.

I was thoroughly happy with their service and was very disappointed that
they declined to quote on my Lancair IVP.  This doesn't surprise me though -
I think my opinion of AIG is higher than their opinion of me. (g)

Good luck,

Hal Woodruff