The RS4 is great but I'm one of the few that don't feel that the avant is the _true_ RS4

But the R8 is not a subtle car - I do love the look of it - such a change from the stealthy RS4 though. Practicality is not an issue for me, but a balance of comfort and occasional thrill is... it must be as happy to commute on occasion as my RS4, but enjoy a good howl at the weekend. I'm guessing that the straight-line performance is pretty much the same, to a point.
Will I regret?
Anyone have opinions/experience on pros/cons?