18ss is a much better truck! Once you break all the things on the RTR and replace them with what comes on the 18ss you will have as much or more in it. Go a head and order all the heavy-duty diff gears that come with the 18ss, as you will need them when you strip all the cheap gears in the RTR. As well as the RTR has the smaller slower motor. I do not have a problem with my pull start motors if you have them tuned correctly. I have heard a lot of people have problems with the Rotostarters. Just read the form. This is just my opinion.