I don't have a mtx4 so can't say much about it. But as spirit is the current model vs. the mugen which the new mtx5 is out already. Should it be easier to get parts for the Edam? For handling the Spirit is very similar to kyosho. The car feel more aggressive compare to NT1. It feels the car have more front end grip compare to xray, atleast my xray. Maybe it is my setup, but it is just my 2 cents after running and setting up these 3 tourings.