We recently switched to One Beacon from the ASCE program. Their quote for a $2/$2 policy was quite a bit less than ASCE's ($10k or so). We trusted the advice of our brocker. He did not like the ASCE program, possibly because he is biased and can't sell the policy, but I'll give him the benefit of the doubt.
He didn't like that Lloyds was the underwriter for the ASCE program. Lloyds of London operates a bit differently than standard insurance companies. I don't know the full details but I believe they have had some problems in the past (our lawyer had similar concerns).
We haven't had a claim against our One Beacon policy so I'm can't comment on that process. His review of the One Beacon policy vs the ASCE policy mentioned some differences:
1) ASCE program had Hammer Clause while One Beacon did not. I believe this essentially means that if there is an option to settle and you opt out of it that the Hammer Clause limits the insurers liability to the amount they would have paid in the settlement.
2) 60 day extended reporting + preclaim coverage
3) Waiver of subrogation. While we have not needed to hand this out it's my understanding that for some larger projects this may be required. The ASCE program wouldn't allow it. We haven't ever been requested to provide it for our E/O policy and I know there are reasons to not want hand this out, it's at least an option on the policy.
One Beacon (at least at the time our broker reviewed) is rated A by Am Best. They are also an admitted carrier in California. See below for info sent to us by our broker.
One Beacon (Including Atlantic Specialty)
Rating:
Affiliation Code:
A (Excellent)
r (Reinsured)
Financial Size Category:
X ($500 Million to $750 Million)
Outlook:
Stable
Action:
Affirmed
Initial Rating Date:
June 30, 1989
I'm by no means an insurance expert, but based on the above and our trust in our broker we switched to them.