When I bought my Tag Heuer Carrera half a year ago, I was afraid the titanium clasp with black pvd coating would scratch easily. But the opposite is the case: Compared to other watches I've worn a comparable number of days (since I keep a precise statistic, I know that exactly) it shows far fewer signs of wear - none I can see, in fact. I don't baby any of my watches, so they all get subjected to the same daily wear and activities.
Here are comparison pictures of the Tag titanium in black with an Alpina stainless steel bracelet and Steinhart titanium after equal wear time.
I have another black titanium clasp on a Porsche Design chrono, but this one was only worn for half as long as the others. Some tiny scratches are visible, but all in all it looks pretty good, too.
Do you have similar good experiences with black PVD / DLC? At least in to my experience, it actually works agains scratches, when done well.