Honestly, they all have their pros and cons.
1. Good Sam and Coachnet will FIRST find a shop willing and able to take your rig. THEN, only after they confirm that, will they then locate a tow truck to get you there. This can cause delays.
If you break down during the night or on a weekend or holiday or in a very rural area, you can spend a long time waiting. Repair shops are often only open on weekdays, so the GS/Coachnet agent can't get that confirmation from them. If they can't confirm a repair shop, then there is no reason to send a tow truck - they have no where to tow you.
On the other hand, if you are far away from home, GS/Coachnet will do the work for you to find a shop willing and able to work on your rig. This saves you a lot of work.
2. AAA will tow you anywhere you want to go. They will simply locate a tow truck and send it out. Delays are most commonly due to requiring a medium duty wrecker or larger tow (not every tow service has them and so they are often busy on other jobs) or because you want a long tow (if you state you want it towed to your home 150 miles away, you will get fewer tow companies willing to take the run than if you want a tow 50 miles away).
However, this doesn't work as well if you are far from home as you have to figure out where to be towed.
For the cost, I recommend getting one of each type. Get AAA and get GS or Coachnet. This allows you to pick which one will work best in each actual situation. And, if one fails you, you can call the other.
I do notice that Coachnet's prices have gone up from a few years ago.
