We dealt with Yorick Karl from AA Insurance brokers and ended up choosing Pacific Cross. He was extremely helpful and answered all my questions...and believe me, I had lots! We haven't had any claims yet so I can't comment on that issue.
We were ready to do everything ourselves but ran into problems when we went to open a bank account. The bank said they changed their policy and had to have a longer visa, 90 days didn't meet their rules. After that we didn't want the headache and decided to use an agent. We couldn't open just a bank account, they wanted to do the whole thing. We used Siam Legal in Phuket. They were very good and it provided some peace of mind.