I have never had a bad experience with any agency, but I wasnt surprised to see SOS was the agency adding the fee.
A family friend rented from them and at check in had to present a credit card for "file" even though the rental was paid for. A month after returning home they were charged $320 for "damage". A broken table. Not only did they not break a table, a $500 damage waiver had been in their contract at booking..so if they had broke a table, it should've been covered. Luckily, said friends father was an attorney...they were reimbursed quickly.
The second incident was further back but Ive never forgotten it. My former cousins-inlaws booked and paid for their Sept. rental in Feb., including pool heat. They arrive and were told the pool heater had broken and the owners decided not to replace it. Months prior. No warning about it prior to arrival from SOS, and a basic " sorry about your luck, thats on the owner not us" response. They never got a nickle back.
Experienced vacations on 'OBX"
will normally do a walk thru through for a ' Check ' for any damages, for they can be report them immediately.