Banjoman, I don't have the magazine in front of me, but as formerNXM5 pointed out, the Crossfire is one of the best stopping cars around.
You're probably correct about the choice of using wider tires as being mostly cosmetic on the Crossfire, but in a head to head comparison test between a 2003 SLK320 and '04 Crossfire automatic, the Crossfire came out ahead of the SLK in the handling arena. Only the SLK's 1/4 mile times were better (by close to a 1/2 sec.) they did say the smaller tires gave it a more supple ride.
Since the Limited Crossfire uses the same brakes as the SLK, the 17" wheels will go right on. My biggest concern would be the offset. I've never had the greatest luck using wheel spacers, but others on the forum have used them with no problems.
I know what you're saying about the Miata, nothing I've driven is more tossable, but since I've purchased our Crossfire, I haven't driven our Miata even once.