There are several advantages of going the ARF route. First, as has been mentioned, you can choose a better engine and radio. Also, I've priced ARF versus RTF packages and several times have found the ARF to be cheaper. In addition, by starting with an ARF, you're learning about installing the engine, radio, fuel tank, aligning the flight surfaces, etc as you're assembling the plane. These skills will be useful for all of the rest of your planes.