I have always had good service from Roaside Assistance especially on my ex ML. The only tow that you get for free is if it is under warranty! MB provides the "roadside" service for lifetime on your vehicle. If your vin is not in MB database they might not (gray market). If you dont want a tow they wont force it on you and you can make your own arrangements,(they can contact a towing company) they will change a tire , bring fuel, and provide a jump. All other services which they provide at roadside, belts hose etc. are billed. I dont understand why there is any whining, most manufacturers dont support their cars after the warranty period, including BMW and LEXUS.
The only time they dont supprt this if there is no dealership, but they will contact a provider such as AAA