Quick enough? Well I guess depends what you're looking for. As for me, I was getting tired of the work and effort required to drive the car at any where near it's capacity. Driving the GT3 was an act of faith, always wanting to push it closer and closer to the edge. No fun to drive 2-3 hours to the track. It was a relief to get where I was going and roll out of the car and relax. Car is always demanding, which is why some people like it. Bottom line is I'm just getting too old to appreciate it and I've been driving racing type cars most of my life. The E63 is satisfying in that if I would need the power I know it's there but it's not in my face all the time. The car treats you with respect as if you matter more than the car does. The MB I enjoy driving and is so comfortalbe and a nice place to be I hate to get out of it. I still find it hard to believe that driving a car can be such a pleasant experience.
Quick enough, certainly, for me is. and certainly not an embarassment to find myself in on a nice twisty country road. Pleasant and fun, what else could you ask?
Ray