I've driven my friend's SLK and I agree with everything you've said about it I think. The only thing I'd add is that the SLK has the same dead steering feel that all Mercs seem to have. I really like the wind isolation though, it's definitely way better than the Boxster's.
However, that windstop is awful. The glare from headlights at night is just ridiculous.
Anyhow, all off-topic of course.
Are you going to go to this clinic?