I've owned 2 C5's - a 97 that had the ZO6 titanium exhaust and an 02 ZO6 that had the stock titanium exhaust. I liked the sound and read that that it was very efficient (i.e. changing to another exhaust rarely gained more than 3-4 HP. Yes, it was lighter - perhaps 1/2 the weight of stainless.
Here's a link that might help
CP2 TITANIUM