They seem durable to me in all aspects. However, you can judge by people's reviews. If you don't find many people complaining about durability, then that is an experience that should be accounted for. Tell me what you like about the XB90EX and what you don't like, so that I can give you an idea about what to expect out of the AH-C300
beside xb90 having great mids, the bass reaches deep, deepest i heard. im not expecting denon to compete directly but i know sony are not the most refined so its hard to know where the denon stand.
..most refined in what?