Just took one out for a test drive... very nice it was too

As I don't have another RS4 to compare it to I just have a couple of questions I need advice on:
Steering
The steering felt fine around the corners but a little strange to me when driving in a straight line. Any slight turn of the wheel was met by quite a bit of resistance with the steering wheel feeling like it just wanted to return to centre the whole time. It also tramlined a lot and followed the camber of the road - so pulled left on typical B roads. I don't know what tyres it had on but does this sound normal?
I'm think it may just be because I'm not used to such wide front tyres?
Brakes
Do RS4 brakes have much servo assistance, if any? I know the standard brakes aren't all that great but these needed some serious thigh power to do anything and didn't actually seem to get much better when I was pressing really hard. I am used to relatively under-servo'd brakes, having come from a Boxster S, but these didn't inspire much confidence. Does this sound normal too or could they be in need of new pads and or discs?
Any comments much appreciated!