Mine is True Temper S3. The tubes are shaped to add strength. For example, the top tube is teardrop shaped and the downtube is ovalized where it meets the bottom bracket shell and head tube.

It is not flexy or bouncy at all. I'm not saying that it is uncomfortably stiff but I also own a Bianchi Pista which bounces like a spring compared to the Rodriguez. The Rodriguez S3 frame is a stiff, sporty ride.

I'm not worried about the frame failing. They make mountain bikes out of S3 tubes. S3 is amazing stuff.