Well for me a solid diff in the back is much easier, but I am using a one-way in font. With a normal diff in the back the car tries to get traction while drifting and I can't hold drifts for as long. I have used both types of yokomo tyres and a type of drift tyre made and sold here in NZ, which work very well on asphalt. I do not change the setup a lot on my car from mod and it works fine.