The last Ti Colnago I had experience with was my friend's early 1990's Colnago Bi-Titan Ti frame. It SNAPPED at the downtube(s) when it was 3 months old. Then the replacement did the same.

He's been riding Litespeeds ever since. Make sure the warranty is good. To Colnago and the LBS's credit they did make good on the broken bike(s) at the time.