Well, coming from the
MK1 Leon, the ride is good but the MK1 was harsh in hindsight (though I miss it). It being the bigger car, it doesn't feel quite as peppy as the MK1 (mine was 180bhp), but it is as fast. I had mid range tyres on before and the rear felt like it would roll away a bit, but now have some Goodyears and it feels more planted. You can get a RS4 rear anti roll bar in what is apparently an easy mod. For now I don't need it (plus it unhelpfully doubled in price over the last year!)
There's no reason why you couldn't get the Exeo significantly up on its stock rating - I think it has the same engine as the
Leon MK2 (197bhp stock, 207lbft torque). Stage 1 is meant to take it to 240-255. Stage 2 should push it to 270-285s, Stage 2+ pushes 300 bhp. But if you head over to audizine people have pushed the 2.0T hard and there are some big figures over there so don't see why you couldn't get higher if you had the time and money.
I haven't actually checked for carbon build up, but it seems to be unavoidable. I keep meaning to take the throttle body off and stick a camera up there to take a look. At 50k and with all I've read, I assume that it will have enough layers that if I get it done now, it will last the next 3-4 years of ownership!