My opinion is that the simple radio systems that come with most RTF packages are excellent for their intended purpose. After you learn to fly, keep the trainer totally intact. Get all new stuff for the next model. By the time you're ready for the next radio system you'll possibly have a better idea of what you want to choose.

By keeping the trainer intact you can fly it when you want, or when your next plane is 'in the shop' because of a crash.