As Mo says, you need to go drive one - it will not disappoint - just don't expect the ultimate sports car experience - a 911 it is not, although being small and fairly light, handling is actually pretty good. Suspensions is hard; harder than the standard car but suits it well.
I like to think of it as more of a sporting grand tourer; for fast road use, you won't find much better - it's a serious piece of kit.
And the figures are a little better than you might have been led to believe - Chrysler agreed to down-play these so as not to undermine sales of the SLK32AMG (which is what it is under the skin), so what you actually get is 349 bhp giving 0-60 in 4.8 secs.
I understand a Eurocharged tune can boost bhp to around 370 and remove the 155mph limiter.
But - unless you're a total maniac, (and there are some on here!) or going to the drag strip regularly, you won't need to mod it - it has enough power to kill you or lose your license in stock form!
One thing I am considering though, is a Sprint Booster which doesn't make it any quicker but sharpens up the throttle response - quite useful in an auto.
See my previous post (#25) about he seller - try an offer by all means but believe me, he won't consider anything 'silly' !