I have had and used GS and AAA for my RV. I have had CN for my RV but did not need to use it. I have found that there are innate differences in the business model for GS/CN and AAA:
GS/CN - you call, they start calling their contracted repair shops for a shop that is willing to take your RV. When they obtain that shop's acceptance, they will call the contracted tow truck companies to find one that is willing and able to tow your vehicle. Unless you have the plan that allows you to identify where you want to have your RV taken, you have to wait until GS/CN gets confirmation from a shop BEFORE they will send the tow truck out to you. Late nights, weekends, holidays, this can be difficult as many shops will not answer the phone. And while the tow service may be willing to tow your vehicle, they aren't always willing to service your vehicle - and while a shop may be willing to service your vehicle, they don't have a tow truck to tow your vehicle. This means that you may be waiting on confirmation by TWO different companies before GS can send out the tow truck. That's why they usually require the mobile service to try to repair your vehicle first - it can speed up the process immensely by only having to contact one company.
AAA - you call, they start calling the contracted towing companies to find one that is willing and able to tow your RV. Then they send it out. They do not locate a shop - that's your responsibility - so they can respond with the tow truck quicker.
Knowing the differences in how they operate is key in understanding why issues occur. Once I discovered this difference, I realized that having AAA and one of the others is my best bet - in my local area, I call AAA and have it towed to my preferred shop; outside my area where I don't have knowledge of repair shops, I call GS/CN and have them find a shop and obtain the tow. Late nights, weekends, and holidays outside my area, I'm at more of a loss - AAA will get a tow right away, but where do I tow it to? GS/CN will find a shop to tow it to, but it could take hours before the tow is sent and I'm stuck until then.