I've had both the 103 and the 104.I chose to stay and focus on the 104 for the reason that I'm guessing it's (f104) the future of Tamiya's F1 class. But Timming is right,the 103 is one fast little ride.The F104 Pro comes with a lot of nice stuff for the money.I'm just being patient and waiting for more rubber tire options . I hope
.Good luck.