The problem is that all the ERS providers contract to local wrecker services for towing, tire changes and other road services. The provider is providing a service for a negotiated rate and will turn down GS for a more profitable, closer or easier service call. Response time will greatly depend on time of day, weekend, or holidays. So if you are in "Boonsville" on a holiday, you may have to wait until they can get out to you.
I have had to wait for a tire change because the shop was not busy, but we were 60 miles from anything in west Texas.
Ken