You won't find any objective differences between these two brands in durability. As in all mechanical goods stuff lasts, stuff breaks. The two brands (all three for that matter including Campy) are very comparable. You can't learn anything valuable from anecdotes which have no statistical validity. On the other hand bike equipment isn't forever. You should expect long reliable service, but you should also expect the need for the occasional repair or replacement. That is just life in this universe. Serious riders who are concerned about durability for cost or other reasons should do their own mechanical work. Parts can be obtained more reasonably on the internet and the mechanical service savings are significant. Most failures are not the result of defects in materials, design, or manufacturing, but rather just the result of hard use. Bikes take a beating. You have to keep them up.