I have made two claims in 2015 using the Amex Platinum Edge card. One was for a 14 hour delay in a CX flight from HKG to TPE (horrendous experience thanks CX) and one was for lost luggage from SQ (flight SYD-SIN-MUC where the bag never left SYD). Both times was very good service from Ace Insurance, claims settled in both cases within 2 weeks and money deposited to my bank account. Pretty easy process, Ace have an online form which you fill in, attached receipts and then they contact via phone or email after that with any queries.
So I am pretty happy with the complimentary travel insurance so far - but I only do 2 overseas trips per year.