I run my cars with these slimline motors (the modern Scalextric & MRRC) with a Parma 60 OHM controller and find it the best thing I ever purchased. All of these cars are now smooth and so much more controlable that they are at last fun to drive .... we use 12 volt car battery as the power supple were I run these.
I've raced the Ferrari from this set a lot and even though it looks quite fragile it's a robust little bugger that can take a ton of punishment and multi car pile ups easily.
Oops, forgot to mention that the rear tyres on both the Scaley Ferrari & McLaren mentioned in this thread are crap and have very little grip. I use Urethane tyres on rear of both of these cars now, and the change in how they run now is incredible.