I have owned a number of T3 cameras and shot with them exclusively for a few years. I don't think it's a robust camera, but it's reliable as long as you are careful with it. With dust and wear, the front lens curtain won't close all the way when the lens assembly retracts. The Contax repairman who saw my camera told me that it's a common problem and that it requires a full CLA to repair. Another issue that can develop is that the film take up sprocket can stop functioning because the tooth that catches the film will break off. Later models or ones that have been repaired have two teeth to catch the film, and from what I understand, these do not break. I hear that as long as you don't put too much slack on the film when you load it, the one tooth sprocket models won't break.
Other than that, I have to say that these little problems are totally worth living with because the camera is just great. Better than the T2 in my opinion; much better resolution images, and I think the color tonality is better too. Klasse S cameras create contrasty images, have a good user interface, are nice and small. I dropped mine from a very short height, and it completely broke. No one was willing to repair it in the US. I opened it up, and it looked pretty fragile inside! This is a very amateur assessment and anecdote, however.