It's brittle, and if you drop it you risk cracking it; it's as simple as that. So, you know what? Don't drop it. :-p
But seriously, I recently acquired a Top Gun Doppel and I have zero worries about wearing it as it was meant to be worn. The case is supremely scratch-resistant, non-corrosive and amagnetic, and it houses a proven, durable movement, so why would I? Will I be careful around door knobs and the like? Sure, just like I am with all of my watches, from the most affordable to the most expensive.
As for your present dilemma, you've really picked two completely opposite watches here, haven't you? A modern, ceramic-cased chronograph or a vintage-inspired alarm/diver that shouldn't be taken diving... Hmmm... Well, of the two, I'd choose the DSA (my preference is for the more unique American dial, however). I don't know quite what it is, but there's something about the MCCC that just leaves me cold. I took a long, hard look at one before I bought the Top Gun Doppel, but at the end of the day the larger, pilot-style case and Habring-designed rattrapante complication of the IWC won me over. Also, the somewhat controversial "Top Gun" association complements my Navy SEALs Diving Alarm Incursion better. ;-)
Good luck with your decision, Kour, but if I were you I wouldn't let any concerns over the ceramic case of the MCCC sway you unduly.
Regards,
Adam