According to the British AutoCar magazine the SVT does 0-60mph in only 7.2 seconds.
That is about the same as a Jap Spec VTiR integra so it must be pretty close to the US GSR.
However I imagine the Focus would be the better handler, but only when compared to the older GSR. (remember its a car that is now 10 years old)
Compared to the new Integra (RSX in the US) Type R (Type S) then I think any differnce will come down purly to driver choice, and I would have to drive both before I made a decision.