i have the 330 i pp which comes with staggered set up. 225 front 255 back.
NOT GOOD. the car has initial understeer, and it is actually hard to drive it on the throttle, without purpusefully digging the brakes in. it is very annoying, and i will go to 245 size all round as soon as i wear out current tyres.
in my hands, it is better than m3 (although obviously much slower), which seems to have more of the initial understeer, probably because m3 has a much stiffer front roll bar than my car.
i would never go to stagger on a stock e46.